Playboy objectifies women, and contributes to the unrealistic body image that hurts women. They use to, at least, (not sure if they do any longer), have women walk around wearing bunny ears and fluffy round rabbit tails on their buttocks, and I find that extremely degrading.
I honestly have less of a problem with straight-out pornography than I do with Playboy. At least porn shows both genders doing their thing. Playboy's message is and always has been that women are only good as sex toys for men. That women are only the sum of their attractive body parts, and if they don't have (what's pitched to men as being) perfect, attractive body parts, then said women are worthless.
Bleeach.