There have been cross dressers for forever.
The thing is this: clothing is changeable. The person is not. Society's idea of what makes feminine or masculine clothing is impermanent. Gender is ultimately a costume. Transgender people are just trying to express how they feel on a range using clothing to state who they are, whether they realize it or not. If you see a big husky confident secure manly man who is heterosexual through and through, you don't doubt his societally determined "masculinity" if he puts on a fairy costume for a joke (aka The Rock in The Tooth Fairy). No. You don't. If somebody is on a range (a spectrum) it's not a challenge to anybody or to society. It's just that society and the culture have made (tried to force) people to fit into 2 different categories. Society and culture change. Costumes change. If people could just let people be, it wouldn't matter to you or anybody what you or somebody else wears as long as you don't have to see their private junk etc.
If anything most cultures were initially walking around in skirts and gowns. Think about that. Jesus, Gladiators, Roman Centurions, William Wallace and his fellow Scots, Ancient Greeks and Persians, Gandhi, etc. Those were gowns and skirts and robes, dude. What made them manly back then? Who the F cares? They're clothes. This is the same reason people complained that women shouldn't wear pants. If anything a heterosexual Western woman who just dresses in her everyday tee and jeans is the most so-called privileged person in the world, because she doesn't have to prove a thing about herself. Western men in the same clothes live the same life. If somebody wants to wear something different, that isn't just "safe" then they are already challenging gender roles again. If somebody dresses "metrosexual" that challenges rednecks. Who cares what rednecks think?