Well, let's start from the beginning.

When talking about gender identity, the two main terms are "cis" – you identify as the gender of your body – and "trans" – you identify as the opposite gender. While transgender prejudice certainly exists, the average person mostly just doesn't get it. Most people don't even know that "cisgender" is a word.

There is a very large transgender community on Tumblr, or at least a large community of people who identify as such. Given that Tumblr has a powerful "echo chamber" effect, it's very easy for members of said community to adopt extreme viewpoints, such as claiming that cisgender individuals never experience any real prejudice, declaring someone calling them by the wrong pronoun "rape," or demanding the deaths of all cisgender people.

Needless to say, since this means the first experience many cisgender people have with the transgender community is pissed-off nerds on the internet calling for their blood, it doesn't do the community any favors, and consequently people like the OP really wish that that particular faction would tone it down.

If only I was straight, I'd marry this brilliant man.