I must agree this strongly comes off as "pretending not to understand". How one feels about being misgendered has nothing to do with whether there's anything objectively wrong with one vs. another. It's insulting that you expect this to be taken as a sincere point.
Okay, I'll be somewhat less subtle than usual here. If you take the trouble to introspect about
why you'd be upset to have someone address you with the wrong pronouns, you might well find that you're actually upset about being perceived as the wrong
sex regardless of your particular gender expression and level of (non)conformity to gender roles.
Suppose I were to run the experiment proposed at #670, deliberately referring to female friends using he/him pronouns to see how they react. Will they become upset with me because I have
missexed them by failing to acknowledge their femaleness, or because I have
misgendered them by failing to acknowledge that their gender identity aligns with their sex at birth? Both? Something else?
It seems at least possible that you are all simply mistaken about
why people would be upset to be addressed with the wrong pronouns, presumably because you have failed to adequately distinguish between sex (something you are) and gender (something you feel).
Contrary to the advice given in the original CU Boulder page, I've found that people (outside of progressive activist settings such as Skepticon) rather rarely take the trouble to ask for pronouns at the outset of a social interaction. Why is that? The only reason that springs readily to mind is that they are using pronouns automatically and unthinkingly to refer to apparent sex rather than one's inner sense of self.