True story: My G string was so tight my nut broke. Ah... the old Fender Squier.
Anyway, interesting thread. The modern tuning system is a compromise. The 5th of G is not necessarily the major 3rd of A#, even though they're both D - one will be a little sharp of the other. If you made an instrument to be perfectly in tune in one key, it would be out of tune in all other keys.
Piano has an even tempered system, and can because each note is tuned individually. 5ths are slightly flat so that when they're thirds, they're slightly sharp, somewhere in between the two places where it would sound right. Guitars suffer from a slightly different (additional) problem where - and I'm a little fuzzy on this - the lower notes on the fretboard are somewhat flat relative to the higher notes. I think I used to understand this (probably from reading on Buzz Feiten's website) but I don't remember anymore.
Buzz Feiten & similar tuning systems are supposed to compensate a for this, at least a little, by sharping the lower notes on the fretboard just a bit. When you reach the higher notes, they'll be flat *relative* to the lower notes, and it'll all work itself out. It isn't a perfect solution - you can't have a perfect solution without having an instrument made for each key (or playing fretless), but it's a step up from what we had before.
At least, that's the theory how I understand it.
As for whether or not it's important for the bass to have this feature because it doesn't play chords... IDK, it is involved in making chords with the other instruments. Does it being a bass making it "2 cents sharp" make it more or less forgiving? I'd guess more forgiving - bass frequencies are giant waves, and I'd suspect the ear is more forgiving to subdivisions of a 14 foot wave being a bit off than subdivisions of a 1 foot wave.
Anyway... Ernie Ball Music Man basses rock. Of all the "$1000 mass manufactured" basses out there, they're the most consistent. I'd never buy a Fender sight-unseen because you never know what you're getting, even American made, but with an MM, as long as it's recent (not 80's) I know exactly what I'm getting. And Bravo to Ernie Ball for experimenting with & using somewhat more esoteric technologies on their instruments.