Quoted By:
They don't, even Gamefreak realized this when they stuffed XY to the brim with Kanto Pokemon. Pidgey, Charmander and Pikachu? All available before the second badge. Mewtwo? Obtainable in the Unknown Dungeon again, with two fucking mega-evolutions. Number of new Pokemon? Lowest in franchise history.
Gamefreak knows what the fans want, and they're giving it to us gracefully.