> Why is it annoying?

Because it affects his concentration? He already expressed that in his post

" or at least why can't it be nothing at all so it doesn't interrupt my thinking"

By having those sorts of thoughts, you are privileging that aspect of them over any other sort of accomplishments they might have. They have less opportunity to present themselves in the way they would like to.

Imagine if everyone around you in your workplace would think about how you're dressed instead of what you're actually trying to talk to them about.

Women have the same instinctive reaction to attractive men though. I do agree everyone should be aware of how attractiveness can influence their perception of another person, but I don't feel guilty about noticing whether a woman is attractive or not and I definitely am not going to make a futile attempt to prevent it.

We live in a society where this issue affects women way more than it does men (see Clinton getting lectured at about not constantly smiling). Bringing this up is part of a fight to reduce systemic bias.

I get that and generally agree. I am more challenging the idea of feeling bad / guilty about sexual attraction, which I interpreted as being implied by some of the other comments in this thread.

I think you are arguing against biology.

I think you are arguing for denial of a fundamental aspect of human nature.

I suspect you're missing the point of the parent comment, and the post itself. Regardless of whether these thoughts are wrong or oppressive, is it useful to fight or deny them? Is it helpful to chastise ourselves or feel guilty for having them?

I understand why you're getting downvoted but I think this is a really good point.