I don't think we're supposed to be celebrating the brain-wiping. I think that's definitely supposed to be leaving the viewer a bit uncomfortable, while simultaneously being enough of a gray area not to make it obvious whether we're watching the bad guys or not.
I'm not so much talking about how it works inside the show, more that he went and found a way to make all-new female characters each week to suit his mood.
Again, I don't mind the show, it just bothers me that it seems to be revealing more about Joss' mind than I care to know. If anyone else had made this I wouldn't be talking about any of this.
I think Dr. Horrible was so great BECAUSE it strayed from this, in fact! I think Joss would do better if he was challenged to work outside his comfort zone more often. (Which is why I bring this up: the reviews seem lukewarm. I'd prefer to see him create successful shows. Hopefully this one does well. I doubt my concerns bother the average viewer so it shouldn't matter.)