<nods> I remember when I first felt the sub urges, I was 24 and it came out of the blue. I could not for the life of me understand what these ideas had to do with ME and the person I was! I struggled with it for more than a year, trying to think it all out. Then I realised that I couldn't. The only way was to try and see what happened. And I did, and it was good. I had had experiences with two very abusive situations (not bdsm related) and they left me devastated. And however much my bdsm situations looked like abuse, it wasn't. But I could not think my solution, I had to try it and then face the facts the experiment gave up.
Later came the dominance <G>
My point is, I believe that the people your mention here likewise try to think their understanding of Ds things. But sometimes you cannot. Sometimes you just have to accept facts. And the facts are, that understand it or not, some people do have both tangents.
I cannot claim to understand it myself, but I think it has to do with some sort of two-sides-of-a-coin. That Ds or BDSM is a whole, somehow.