>>725354960
Nah, that was Masuda's idea. Tajiri wanted a grandiose romp through all of PokeJapan, and Kanto was comically truncated in that original vision.
But when Tajiri was fumbling so hard with game development that he couldn't meet his personal deadline, he completely gave up and it was up to Masuda to take charge and repurpose the game into something that was actually able to be made and released in order to strike while the iron was still hot.
Masuda's Kanto fixation continued long after this, of course, as seen with such famous instances like DP's Pokedex being exactly 151, just like Kanto, BW being a soft reboot full of Kanto expies, XY being full of direct Kanto throwbacks and tons of Mega Evolutions for Kanto mons, basically unknowingly fulfilling the PokeGod dreams of Pokemania kids at long last, and the list goes on.