Not quite what's being discussed here, but... there's one young men's clothing chain here that I am wary about shopping in. When I was younger, I went in and went to try on a jumper and was told I wasn't allowed as the changing rooms were for men only. There was no separate female changing rooms — in fact, unisex changing rooms are the norm here.
I wasn't trying to pass at all, so I didn't say "But I am a man!" or anything. I live in a different city now, so perhaps I'd have more luck these days and/or it isn't a nationwide policy. Even so, it puts me off shopping there! All the staff were women, and they were allowed in the changing rooms, so why only male customers? I know it's a men's clothing shop, but they sell some fairly unisex clothing...

I don't see why it was such a big deal.