Edit: oh, this poster thinks hitler was an admirable figure. Ok, nevermind, no need to entertain their words anymore: https://news.ycombinator.com/item?id=31722179
Your assertion that it is certainly not aways been here, is wrong. Examples in history are plentiful. From shakepearean actors, to two-spirit people in the americas. Gender is somewhere between 50% and 100% a social construct. We construct it differently in different times, but the desire to construct it both as a binary and as a fluid spectrum are as human as breathing.
Trans people (and gay people, and bi, and asexual..) exist and have always existed - it's only now that modern medicine is capable of and permitted to let them shape their body in the way that matches their identity. It also happens to be during a resurgence in anti-LGBT rhetoric that's part of the MAGA "we had it right in the '50s" dog whistle. Their activism is a natural result.