I'm really not following how you can imply that anyone who's been sexually abused can't be a balanced person who understands what they're getting into when it comes to BDSM. I admit that I was molested at a young age, but I've managed to grow since then. I didn't walk into this lifestyle blind to my options. I chose it because it suits me, not because it's all that I know.

Now, I admit that it's possible for someone used to abuse to to continue to seek it out simply because it's what they know, but that's not a given response for all people. The fact that someone has been abused really impllies very little about who they are at present, which is really all that should matter.