This show is amazing. And dark. Very, very dark. This has clearly made many people uncomfortable. However, Helo, sorry, Paul, essentially spells out the message in the pilot: when seemingly helpful technology is created someone finds a way to use it for evil.
I don't believe the show makes any apologies for the people at the Dollhouse. I believe it shows the ways those people rationalize what they are doing so they can sleep at night.
This show is a great vessel for exploring the nature of the soul and personality. What makes people who they are. Despite being wiped and implanted over and over, Echo retains some of her Caroline-ness. This show is not ultimately about "the world's oldest profession," but about what makes humans human. If you can't get past the creepy paying for people, and, yes, the singer episode, then this is really not your show.
And, speaking as a woman, I really don't find it all that offensive. I'm actually not all that certain why I should. The dolls are of both sexes and I see a strong female lead, may Whedon continue to put them on television.
I highly recommend this show. Get past the first few episodes (which Fox tinkered with) and see the brilliance beyond.