>>54897259I think the biggest issue with Gen 4 is it wildly succeeded in a lot of areas, and was a total flop in other areas.
Physical/Special split was awesome, has arguably the best Battle Frontier in the series, tons of Legendries to post-game hunt for, a surprisingly well balanced starter roster for a casual playthrough at the time.
On the flip side, the game has worse Pokemon variety than Gen 1, basically making everyones team the same unless you actively go out of your way to avoid the likes of Staraptor and Luxray. So many of the new pokemon are locked behind post game, trade evolutions, or one time use stone items casual folk might be hesitant to use. A lot of it's identity as a Pokedex is tied around evolving past forms, with mixed results.
It plays well in almost all aspects but casual team building, which it is undeniably the worst in. That's why, despite enjoying Gen 4 a lot and it being my 2nd favorite Gen, I understand when people say they don't like it.