So, yes, insecurity but primarily insecurity about losing power and control, by men. That's why we focus so much on what "she" wears but nobody gives two shits if I show up to work in flipflops, board shorts and a tank top. Why would they? I'm a dude.

Feminism has an extremely broad remit and it's all based on the idea that actual ideology routinely boxes in half of the population in some way or another. It's just a fact, and thus there is endless study that can be undertaken.

Men get made fun of for what they wear all the time. So, I don’t get this argument that no one cares what men wear because we all certainly do. See mens wardrobe options vs womens. Compare the two - look at what is normal for one and normal for another. You’ll see one has far more selection than the other.

I think another aspect is that men's fashion is inherently more limited - because - men are aware of the critiques and don't want to deal with it.

Interestingly enough, this probably applies to the people who were dismissing Obama on the basis of that tan suit as well.