>>19967438Mostly because of how over the top it was.
I mean, there are pokegods that essentially have control over reality and the one god that rules them all.
Does that not sound a bit much to you?
Also there's the whole issue with the speed, sure HG/SS and Platinum increased the speed but it was so incredibly slight outside of the surfing that you would have to literally, for lack of a better word, be autistic to notice outside of the surfing. They also dropped frames in certain areas, which is sloppy for a predominantly sprite based game.
Then there was the distribution of the pokemon, D/P had no fire types outside of the Chimchar and Pontya lines until you reached the postgame and the crossgen evos were put behind a barrier so you couldn't get them until you saw all of the pokemon in the Sinnoh dex.
Platinum fixed it to an extent and removed the barrier but there was still a woeful amount of useful fire types for players to use.
HG/SS didn't improve much on the original either with gym leaders still showing a noticeable lack of Johtomon that would have made sense for them to have and show off. That and the level distribution and GB sounds disappointed a bunch of people.
There's also the battle frontier, but I don't think I really need to go into detail about that. You just need to look at the Emerald one and the Gen 4 one.
Anyway that's about it really.