I feel that’s looking at things with rose colored glasses. Yeah they’re revered now in comparison to the newer games but they received plenty of criticism when they were first released. Same could be said with Gen 3 before ORAS pumped new life into it. Through it all, I never paid attention and just played what I wanted.
THIS.
THIS.
THIS.
Shock of all shocks, people tend to forget that almost EVERY pokemon game was criticized after Gen 3 (and that's because at the time, that was due to the lack of the online presence or how the internet was still evolving at the time). In fact, Diamond and Pearl were released at the time where the internet was starting to get more traction and sites like Youtube were a thing and forums kept bustling out and talking about the games as a whole.
Hell, I remember all the bitching and complaining about Generation 5, and how people hated the fact that you couldn't catch your old favorites in the game... Which was a bit of a lie, since you could, but they were locked behind completing the story.
GF tried to release a sequel to the games, trying to remedy this, and they did, heck, you could catch Riolu in the wild and get a Lucario on your team (remember, Lucario was one of the hottest pokemon at the time... Oh god...), but unfortunately, the damage had been done. When they released BW2, they managed to scrap over half of the amount of sales that the original games did. Which is actually a trend that we see if you look at the sales of the third games in the series:
Yellow, Crystal, Emerald, and Platinum. And that's mainly because they're more fleshed out versions of the previous two games with added features to them. And I wouldn't be surprised if people thought the same with BW2, given the trends of before - And yes, I'm willing to believe that people are that dumb.
I've recently seen people praising X and Y, but I have an issue with that. You can like the games sure, but to me, it's probably one of the weakest entries in the entire series, especially coming hot off of the heels of Gen 5, which, fun fact, both gens were being developed alongside each other.
To me, the series reached it's height in gen 5 - With it's game design, aesthetic design, and even it's sound design, like, I still love how the music would change in battle depending on how much health your pokemon had or when you reached the last pokemon the Gym Leader had, that small change really pumped you up.
But considering that you had so many people complaining about Gen 5, as well as the lack of being able to catch previous pokemon, I believe that the heads of GF and TPC took that the wrong way and had gens 6 and 7 focused more on catering to the Previous Generations, and thus took a lot away from making the generations stand out.
