I am personally of a split mind about this. It's true that we could be simply blinded by nostalgia and unable to see the greatness of these new Pokemon. But I think I can tell what the problem is. It's not that we're outgrowing Pokemon itself, but we're leaving the target audience, which makes us feel like the games aren't quite for us to begin with. Think about it - you're forced to become a 10-year-old child before even starting the game, doesn't that sort of... not turn you off to the experience, but... take you out of it? Like, you feel like you're not becoming the main character anymore.
And the Pokemon mirror this idea perfectly. Say what you will, but Muk is way better than Garbodor. Why? Just look at their expressions. Muk is like, "Gwaar! I am a big pile of sludge! Don't touch me, because I may burn away your skin!" It perfectly exemplified how sludge would feel if it came alive - vile, disgusting, and acidic in more ways than one. Then look at Garbodor. It doesn't look particularly vicious (which is part of the danger aspect that I'll cover later). It's got an expression that can be summed up in two words: Herp derp. Come on, if your garbage, complete with slime, came to life, would you'd expect it to be a little frightening? Garbodor looks pretty apathetic, in my opinion. I mean, they're Pocket Monsters
, after all! Not Pocket Pets!
And that smoothly brings me to the danger aspect. Here, I'll make a comparison to outside media, so you might need to be a bit cultured to get everything. First, think of Mewtwo. It may be small - it's about human size and weight - but it still has incredible power, and that's exemplified by the silently furious expression on its face. It's a perfect example of the fat that you don't need to be a giant dinosaur-like creature to be evil and frightening. You don't need to roar and scream, or be able to smash through walls with sheer brute force. Reshiram and Zekrom take this and throw it out the window. Granted, previous generations were victims of this, also. Groudon, Kyogre, and Rayquaza were bad. Dialga, Palkia, and Giratina were worse. I mean, bending time and space? Controlling an alternate dimension? That's a bit too much for me. There's nothing on earth, animal or otherwise, that is anything remotely like Dialga, Palkia, or Giratina. My point is that all Pokemon should be able to have a dangerous side, without having to be big and intimidating as well. Just think of Dragonite - it may be gentle, but it's very intelligent. If you get on its bad side, watch out - it's got a nasty Hyper Beam! And before you start screaming, "Slowbro!" or the like, let me remind you of a wonderful anime called Dragonball Z. Think, if you will, of the first form of Janemba. That guy wasn't remotely frightening, except when he walled Goku with his mass and then used his incredible powers to teleport and start conjuring balls and stuff. That's what Slowbro is like. It may seem cute and cuddly, but when it battles, you'd better watch out, or you'll be walled and destroyed with Psychic powers.
Next, Pokemon should be more animal-like. Now, I don't mean every Pokemon needs to be based on an animal of some sort. What I mean by this is that each and every Pokemon should be comparable to something on earth. Magnemite? A magnet. Diglett? A mole. Jynx? I don't want to say it, but you all know what we're thinking. Now, what the heck is Dialga? Some sort of... time-warping... colossal...levitating...bug thing? What's Metagross? A living cyborg... supercomputer... thing? Product of Pokemon and computers? My point is that the Pokemon may not be getting more complex or overdesigned in terms of graphics, but Gamefreak is ignoring the vast majority of the animal kingdom, along with many amazing things on this earth that would make wonderful Pokemon. How about an amoeba Pokemon? Perhaps a cloud Pokemon? What about an earthworm Pokemon?
Another problem is the lack of real new gameplay mechanics in Black and White. Now, what does this mean? Red and Blue - started it all. Created a worldwide phenomenon that lasts for decades. Gold and Silver - added the time system, as well as held items. Held items were obviously one of the most longstanding and important additions to the series. Ruby and Sapphire - added the EV cap, Choice Band, Natures, and Abilities. Abilities have since become a very important battle aspect. Pokemon Diamond and Pearl - gave each move its own type and added WiFi play. The physical/special damage split changed the way Pokemon was played hugely, and gave some Pokemon new tools, while reducing the danger of others. In one fell swoop, Gamefreak added a new level of balance, and made the games make much more sense to boot. Of course Bite is a physical attack. And that's not even mentioning Choice Specs and Scarf, which added a greater balance as well as new threats. Pokemon Black and White - um... Dream World? Too much work to set up, and you get maybe a new ability for your trouble? Some new berries? Wait, why can't you get those in-game again? Uh... TMs never go away? Oh, wait, that took away a level of strategy and the concept of saving important items for important Pokemon. That new mechanic just made it a much easier game, which really just shows even more the target audience for this game. Kids shouldn't have to work
for things! Saving valuable things and waiting patiently for the right time to do something? Kids don't need to know that! I mean, it's not like it's a life skill or anything! Oh, wait, who's the target audience for this game again? Right... Gamefreak just cemented its target audience as every kid in the world. Great. Just great.
Also, Pokemon has been losing its mature audience. To all intents and purposes, Pokemon was a pretty deep game. Team Rocket wasn't just a bumbling group of manipulated weirdos, nor were they doing random things like thrying to control other dimensions. They were a group of real scientists, and they were literally taking over the region around you. You'd go into, say, Saffron City and find them patrolling the streets and blocking most of the doors. And they performed real experiments - they dabbled in cloning with Mewtwo, which raises the ethical question: Is cloning right? Is Mewtwo justified in its anger at being a clone? The most ethical question Black and White ask is whether Pokemon should be kept in Pokeballs. Big shocker - the game skims over the question with an, "Of course they should be, Billy. Now go catch that giant dragon thing so you can prevent Team Plasma from... what did they want? Rule the world with the help of a giant beast? Ah, nice and generic.
Finally, the portrayal of Pokemon in outside media. This problem is unique in that it started off bad at the beginning, but only got worse as time went on. Pokemon may have been a deep game, but the anime was determined to work against that with a more kid-like theme. It also seemed determined to ignore all gameplay aspects of the source material, which consequently made people worse battlers (go for the horn, Pikachu!). As time went on, it only got worse - Brock was taken out for a short stint, but returned when whoever made the anime decided that they should let the popular characters remain. Then he remained throughout the rest of the anime, slowly devolving into a comic relief character who somehow became an expert on all Pokemon without any research materials. Misty was tossed around a lot, the expert May was defeated by the amateur Dawn, and the show's new characters are determined to get Pokemon a spot on Nick Jr. And this isn't an isolated problem, either - I know many people who won't touch a Pokemon game because it looks babyish in the anime, and I can't say I blame them.
That all said, I don't completely hate Black and White. I like Volcarona and Chandelure, and the main characters are a bit older. But in addition to all the problems that I listed, the graphics in-battle are abysmal, not to mention the camera seems to be going insane when you don't make a move immediately. Also, the bridges were incredibly annoying to cross. And why was the game set in New York again? Last I checked, no one was complaining that the game was set in Japan. And there many minor things too, like the fact that Casteliacones were so hard to get yet so useless, and the fact that you have to cross through that one area of sand whenever you want to run through Route 4. All in all, I think Pokemon is geting worse, but then again, this could just be a senile rant.