The whole "cis" thing started off as kind of a joke on a trans usenet group, if what I've read is correct, and the fact that 99.7% of people (according to wiki) are now, in some quarters, at least, expected to identify themselves as such, and feel guilty about it, boggles my mind.
I'm 100% okay with people doing whatever they want with their bodies, but I kind of think the whole trans thing is weird when considered a medical issue that requires hormones and surgery to correct. We've been around for a couple of hundred thousand years, by some counts, and people have existed across the gender spectrum without hormones or surgery. Different cultures used to accommodate those people in different ways, not all the best ways, but there are plenty of examples of cultures that integrated what are now called "trans" people in healthy ways, seemingly, at least.
And if we're supposed to be against binary gender roles, doesn't "transitioning" kind of spit in the face of that?
I can't stand the term, but maybe it would be better if more people were "genderqueer", though, again, I'm 100% fine with people doing WHATEVER they want with their bodies. I guess it's the medicalization that makes me feel uneasy.