I agree. I'm going to come out and say it, it's difficult for a woman to step into any kind of leadership position and do the tough things without being perceived as a "bitch".
One thing I've observed in women who might be perceived as successful in those roles is that they're able to find the right way of being in charge and overcoming those perceptions. I think it's a subtle attitude or behavior change, and it seems to be a fine line.
But I'll also say that for men, they risk being perceived as "an asshole" in much the same way. And demonstrating assertiveness and leadership, being tough when it's needed it also a similar skill. I just think that men have more societal support and a few thousand years more practice and training to figure it out.
Women have far fewer role models to pattern after.