acrobats are defensive rogues, sure, but that doesn't mean that they should be dex-based. once geared, at least, a few extra points in dex are not going to be of great value.
that said, when you do the math for raw DPS, a dex-based acrobat using dex-based quarterstaves actually have very close to the same DPS as a strength-based one... provided the target is subject to sneak attack.
(that is, 1.5 * strength + dex is often quite close to 2 * dex, which is what the dex-based quarterstaves offer).
the main problem is that you find yourself limited to only a couple of different quarterstaves. this may change in the future, especially if the devs change something in the enhancement update to (at the very least) allow quarterstaves to be finesse weapons. that said... who knows when the enhancement update will hit.
imo: acrobats should be strength-based. the sheer variety of options it opens up is too much to pass up on.
but not everyone will agree with my opinion, and that's fine too