Sometimes on television commercials, especially the kind of low budget commercials you see for local businesses, I've seen women gesticulating with very forceful, masculine hand movements in an attempt to sell something. "You know you'll get the best deal at Handsome Hal's!" And, to me, they look like fools. That's how they strike me. Stereotypical masculine gestures on a woman are an even poorer fit than they are on a man. That's my opinion, anyway. But I bet many people of both sexes share my opinion.
Does that mean women make terrible sales people? Not at all. Does that mean that women have to coo and act coquettish to sell things? Again, not at all. They simply have to adapt their speech and body language to seem more natural. Otherwise, they seem like they're aping men.
You can see the same thing in rock 'n' roll, though you see more of it years ago, in the '70s and '80s than you do now. Female bands and female band leaders tended to ape Led Zeppelin. But, what I can see as having happened since is that women have more successfully integrated a more naturally female persona with music—and lest you think I'm talking about the vixens and playthings, I'm not.
So, what's my point? It's the same at the start. Perhaps many women negotiating in business are doing it poorly. Perhaps, lacking enough female role models, and the confidence that comes from role models, perhaps they're aping men and looking foolish. If anything, the idea of transexuals experiencing this after transitioning supports my opinion.
I think what we have here is some kind of sex-based variation on the Uncanny Valley.