Yeah, I agree. The results Siri returns are from Google or WolframAlpha, so a lack of information on one subject is not necessarily Apple's oversight. I think that the abortion-directions issue was later attributed to Google's SafeSearch filter.
Siri uses Google by default. I just searched google local for "abortion", and Planned Parenthood was in fact listed. If SafeSearch filter is turned on, then it should not be finding prostitution providers either.
Google search results are vastly different these days depending on who (or what) is searching. My guess is that 'who is searching' in this case is a box in a datacenter, somewhere in the midwest.
