Wow, I actually came in here so I could potentially have a legit anti-gen 5 meme but almost all these reasons are stupid, either being shit you have to go out of your way to do, or things that are completely subjective.
Only real valid complaint here is the horrible black city/white forest system as well as the challenge mode system being some ridiculously convoluted thing that requires completing the game and erasing your save file or another system rather than just a difficulty select. Also any features tied to the now defunct dream world. I guess seasons were pretty dumb too.