>>50230669Because Bulbasaur was the most marketed.
it refused to evolve in the anime, and Ash's Bulbasaur is a fanfavorite.
in comparison, Blastoise and Charizard were more marketed than Squirtle and Charmander and people like these much more than their prevos.
And nobody cares about Charmeleon and Wartotle while Ivysaur got more fans because of Smash Bros.
it's all about marketing and exposure, kid