Basically it's members of a discriminated-against minority attempting to discriminate against, and one up each other.
Normal person: "Dude, why would anyone think it's trendy or desirable to be part of a misunderstood and ostracized gender minority? Maybe she just doesn't feel the need to take things as far as you have? Why can't you respect her choices?"
Transgendered blowhard: "Shut up, I'm trans, you're not, and I speak for my entire community!"
Person B - *sighs* another Transtrender