What makes anyone want anything? It's a preference; I'm a submissive, I'm happiest with a dominant partner. If I'm independent, it's only because I have to be. I'm not strong-willed at all, haha. I'm sure my history plays a roll, and I think it's quite common that women who spend their professional lives being in control want to give that up in their personal lives, but as that's not the case for me I don't know.

Your question seems to imply that being independent and strong is better than being dependent or submissive, and I reject that idea. Some people are happiest in an equal relationship, some people are happiest in either a dominant or submissive role - none of those choices are better than the other, it just depends what makes you happy.