>>54196162Because it forces you to go through entire wall texts of plot every few steps, the annoying rivals chase you around and challenge you way too many times, the game begs you to like them and be friends with them but this only makes them feel fake-deep and even more unpleasant, you are forced to use only Gen5 Pokémon for most of the game (in BW) whether you like it or not, the game takes itself way too seriously in a way that makes it feel like a task more than an actually good experience.
Gen5 was a polished generation from a technical point of view, but content-wise it's one of the least appealing to me.
I was a teen when it came out, disliked it then, dislike it now.
I feel like it appeals to a very specific kind of audience (besides kids), which is why it wasn't very appreciated overall.
Nowadays it's overrated simply because Pokemon fans always rehabilitate older games when new ones come out.