it is male anatomy
What's visible to, and possibly disturbing for, the people in the changing room is what it looks like. I don't know, e.g., whether you would consider a post-op female-to-male transsexual person's anatomy male or merely male-looking, but I take it it would be about as disturbing in that context as a straightforwardly cis man's. So the relevant question is what it looks like.
I can change genders at will
I am pretty sure no one is in fact proposing that people be able to change their gender at will simply by saying "I'm a woman now". (Yeah, you could read Fluttershy's comment upthread that way, but I'm quite confident it wasn't so intended.)
I tend to be very cynical about such agitprop.
Good! But I can't help noticing that your cynicism has been deployed only in one direction in this discussion, even though (so it seems to me) there's plenty of moral-outrage agitprop coming from elsewhere.
I can change genders at will
I am pretty sure no one is in fact proposing that people be able to change their gender at will simply by saying "I'm a woman now".
No, you're proposing that anyone can change genders at will by saying "I'm a woman now" and make an attempt to look like the other gender, dress like the other gender and insist on being referred to by opposite gender pronouns and name (that's how you defined "presenting as the other gender" here). While this is technically slightly more then saying "I'm a wo...
There are some long lists of false beliefs that programmers hold. isn't because programmers are especially likely to be more wrong than anyone else, it's just that programming offers a better opportunity than most people get to find out how incomplete their model of the world is.
I'm posting about this here, not just because this information has a decent chance of being both entertaining and useful, but because LWers try to figure things out from relatively simple principles-- who knows what simplifying assumptions might be tripping us up?
The classic (and I think the first) was about names. There have been a few more lists created since then.
Time. And time zones. Crowd-sourced time errors.
Addresses. Possibly more about addresses. I haven't compared the lists.
Gender. This is so short I assume it's seriously incomplete.
Networks. Weirdly, there is no list of falsehoods programmers believe about html (or at least a fast search didn't turn anything up). Don't trust the words in the url.
Distributed computing Build systems.
Poem about character conversion.
I got started on the subject because of this about testing your code, which was posted by Andrew Ducker.