Bolt on has it's benefits, and neck through has it's benefits. Each one suits a different player, different instruments, different manufacturers and their processes.. Bolt-on necks seem to more prevalent for mass production, as i'd guess they're easier and cheaper to do, whereas many people opting for a custom build go for a neck through option. It's all down to what you want IMO.
I will say that although my main bass is a Fender, i do sometimes find them a little bit boring, which is why i want a metalflake pink P bass with matching headstock and fretboard LED's, but at the base of it all, it's still just a P bass.
Liam