I don't get why the N64 is totally lacking in the RPG department.
Pretty much all the third parties largely jumped to the Playstation because of cost issues. It also came out sooner, by over a year in Japan.
N64 ownership in Japan was abysmal (it lost to the Saturn there!), and the western market for JRPGs wasn't really important until FFVII AFAIK, so it didn't make much sense to create RPGs for the N64. FFVII created a mass western market for them, but it did so on the PS1, so where do you think the other companies following the trend put their games? I think Square in particular only developed games for PS1/PS2 for several years, which is a big chunk of a potential RPG library right there. Paper Mario came out too late and Nintendo themselves never really did much else to show there was a point to developing RPGs on their system.