Interesting. I guess it depends on where you're at (stage or audience) and your political views. In most cases drag shows are just what they are, but it's when members of the audience translate that to everyone trans and we've all heard it. And as Pam says, it is used by some groups to entice fear or label group(s) of people. Do we blame the performers, the show, the audience, or those using it to create fear or hate?
And if the performers are deliberately mocking or exaggerating traits in genders, where does it cross the line from humor to politics. We all laugh at these shows and occasionally feel a cringe about some act or behavoir that hurts a little. Some performers deliberately push the limits of social and personal tolerance to illicit that same response. And we've all heard the outcry if the performers challenge social norms but rarely when the performers challenge other groups, eg. LGBT.
Pam also makes a good point that historically we've always made fun of some group, class, or ethnic group of people. It's sometimes human nature which people use to make themselves feel better than someone else. Eventually the outcry overcomes the acts, but somehow drag shows have stayed both in the mainstream and in private. And it gets back to the performers and their reasons for the acts that makes the difference.
The problem is that while it's two sides of the same coin, it's still one coin and both sides are there. And no matter how you look at it there always is some form of intentional discrimination going on. Since we can't get rid of the coin, as someone will always see one side or the other we can only speak for ourselves and maybe simply hand the coin back and say, "I'm sorry, this isn't my coin."
Anyway, just some thoughts.