But it becomes circular and self-defeating when it becomes its own rationale.-AS
Until it is done, it is fine for it to be its "own rationale", to some important degree.
I doubt it is Hillary's core motivation for running. However, when one stands astride history, one is protective of one's place in it, not to mention that it is grounded in the reality that many people are/were anxious to vote for a woman. So, this is the part of her candidacy that is least worrisome to me, frankly. When you have a chance to be remembered for all of history as the first woman American President, you don't kiss-off so easily, you fight for the prize ...
As for being bested by Barack and Bill, I'm also unconvinced. It was Andrew himself that brought up the anecdote about signing the dollar bill. And just because Barack ran an outstanding campaign doesn't mean he is a "better politician". You may not have liked the Clinton campaign, but it was highly effective politically.
In the end, she settled all the questions about her electability, to the point that even old adversaries were convinced that either potential nominee could win the electoral college.
Consider where she started, with high unfavorables and Senator Dodd questioning her on stage about it, that's no small feat (I don't think).