Basically, he asks why does it seem Trannys have only come out in the past generation or two? As a student of history it's always been apparent to me that homosexuals have been around since the dawn of time and can basically coexist and get shit done despite this. But Trannys? This is a new thing as far as i can tell.
There's always a certain number of people who want to push the envelope. Being gay isn't edgy enough these days.
Also, crazy people latch on to things they hear about. I'm sure there's a name for that.