>>59026770It's not the fact they're in the game. It's the fact that despite the game having a large dex, the Kanto Pokémon are far more prevalent. Almost every trainer team, almost every route. They're everywhere and solely for the purpose of nostalgia. That's not the only aspect of Kanto pandering either. Santalune Forest is 100% identical to Viridian Forest even down to most of the wild encounters.
But those aren't the only flaws. Linearity and handholding. Sure you can argue that earlier games started the trend, or that later games did it worse. Doesn't automatically absolve XY from doing that too. Then there's the difficulty. Even if all Pokémon games (minus USUM for many) are really easy, XY takes it even further to the point that there is NO CHALLENGE at all.
That's just a bit. I'd recommend playing the games and doing your own research.