I don't think there's a chance in hell Kojima would've formed a studio to make exclusive Nintendo games. They just don't have the hardware for him to do the kind of things he likes to do.
Switch is an improvement over PS3 and he happily worked on that, and what he's working on for PS4 doesn't seem like it couldn't be done on Switch albeit at lower graphical settings. Ultimately what I'm saying is you're wrong.
Besides, $$$ > all