Kanto is definitely overrated.
I feel like the reason so many people hate on it now, is because gamefreak keeps pandering to them, grasping at whatever they can to get old fans back, Pandering is fine, when done in reason.
Put some kanto mon in the game, give them some new forms, new megas, new evolutions, even have characters from gen 1 show up. But make sure you give the same treatment to everybody else.
If all the focus goes to gen 1, people get tired of it.
I'm fucking sick and tired of gen 1 by now.