Does theory come from experience?

Over in the continuing blogthrash at Rage Against the Man-chine, ND calls someone out for giving personal anecdotes and no discussion. Basically, the person described her scenes and said "how can you call this wrong?" ND didn't like this one bit, pointing out that she's debating about feminist interpretations of BDSM as a whole, not talking about particular personal experiences.

My response:

ND,

While I understand your frustration with the personal anecdotes and agree that they don't count as argument, I also think there's something particular that this disconnect brings out:

One side is saying that personal anecdotes do count, because the personal experience is all we've got. "What BDSM means," on such a view, is just what commonalities and themes can be found in thousands of personal stories. It's whatever reasons for it, activities, and explanations are most common, most appealed to, most important. On this view the only way to come up with "what BDSM is about" is to read as many stories as possible (or, failing that, to come up with a sound method of selecting samples) and discover what you find.

The other side -- which you're on -- says that a theory that makes no reference to actual experience can and does explain it, and therefore individual experiences are irrelevant and beside the point.

But my question is: what makes the theory itself one that we should accept, then? As I understand it, radical feminist theory itself arose from practices like consciousness raising, which was lots of women in groups sitting around describing their experiences, noticing commonalities, and coming up with theory that explained those commonalities and how to work to fix the problems that showed up over and over in the lives of many women.

Now, I wasn't around in the '70's, so perhaps some second-wavers/radical feminists who were can correct me. But my question is: What exactly happened? Why does theory now trump experience, when commonalities in experience were precisely what led feminists to determine that sexism wasn't just a personal matter, but rather a political one?

It really confuses me.