I hope its OK for me to post in this thread as I neither have real BDSM experience nor have I been abused but I would still like to comment.

I don't like uncertainty, the more variables I can eliminate the happier I am. I want to know facts, I want to know what will happen. I don't like it when things go unplanned. A possible partner who is tied up has fewer actions she can take, therefore I am eliminating variables. Even though the possibilities I eliminate are fairly inconsequential it still provides some benefit to me.