To a large extent Fender did get it right with the P and J bass body shapes. They fulfill the essentials of balance, access, and comfort etc. If pretty sure that when they came up with them they didn't just draw a shape and say "That'll do". Even the P & J shapes aren't really that far apart. These shapes can be tweaked by other companies, but in many cases coming up a dramatically/instantly recognisable different body shape is to the detriment of basic function.
They same way that the vast majority of cars are basically the same shape.
IMHO of course.