Because it's relatively little-used and not all Ob's are able to do it (i.e. have never done it) and because most hospitals have a policy of only inducing for medical need and thus the benefit of the foley induction (that it can be stopped and resumed days or even weeks later) make a mockery of the system - either it's medically necessary to get the baby out ASAP (in which case get the big guns out) or you don't need to do an induction of any kind. In addition it is not suitable where there is infection in the vagina or cervix or where strep B is suspected or known to be positive.

The exception to this is becoming (and will become more - talk to your Ob about foley induction (there's a WHO page with info about it here) in cases when a woman is aiming to VBAC and thus cannot have a chemical induction and declines ARM.

Bx