Having a mild discussion with someone I don’t know, and the subject turned to correct grammar.
I mentioned that I appreciate being corrected. However, one time someone told me that it was improper to use a generic “their” to cover a person whose gender is no known. It is proper to say “His or her.” I tried that for two years. It is so clunky that I finally said fukit and reverted.

This guy came on with a fairly interesting comment on that. I will paste and cut:

Him: the “they” issue is complicated. While using “his or her” is grammatically correct, it is also, as you say, really clunky, since one has to keep repeating “his or her” every time a pronoun is used in the sentence, which ends up sounding incredibly awkward. I believe that “his” was the favored pronoun throughout much of history, until feminism became more mainstream and widely accepted. At that point, it became insulting to women for a writer to assume that the subject of their sentence (see what I did there?) was a man. I remember hearing about this in the mid 90s when “political correctness” first became a hot topic of conversation. I do think the PC movement went to far in this case, only because it made writing so needlessly complicated. One is not necessarily a misogynist if he uses “he” instead of “she”. Most likely, he’s just practical. I think everyone is starting to agree that, while grammatically correct, the use of “his or her” is overly cumbersome and are thus reverting to the much simpler “their”. Languages naturally evolve over time, so I wouldn’t worry too much about people nitpicking your choice of pronoun. Now, if you’re really a stickler for always using correct grammar, the simplest way to deal with this problem is to just pluralize the entire sentence.

Me: I disagree that it’s just practical and fine to use “he”. How would you feel if the standard reference was “she”? “Was she a doctor? Was she a lawyer? Was she a rocket scientist? Was she a brain surgeon? Was she an engineer?”
As for me, I will stick with “their” if I don’t know. We just have to make it so common it becomes correct! We can do that you know. Mahhhh!!