Yes, I am in fact okay with refering to every teacher as he, because that's what grammar in my native language demands ("Lehrer, der - masc."). I will also happily refer to every guard as she, because –again– grammar ("Wache, die - fem.).

Genus != sexus != gender... One is grammar, one is biology, one is identity. Overlaps are purely coincidental. I don't understand why especially English speakers can't get the concept. I mean sure, they dumbed down their grammar so much that they lost the destinction, but even unrelated to language they seem to develop an insane fetish for conflating sexus and gender somehow. For example if you need to add "biological" before "gender" for your expression to make sense, that should be a hint that you are actually talking bout different things.

Fun fact: When English tried to move away from gender specific words and towards generic ones (all being actors, instead of speaking about actors and actresses), other languages did the exact opposite. Because when you language's grammar has all nouns (arbitrarily) gendered, actresses and actors is a step forward from the generic actor (which often is male my grammatical definition). At least that was the theory in both cases. Two languages, two exactly opposite reactions to same fact. Why doesn't it make any sense? Because it's a fucking narrative to keep some culture war bullshit going. Language isn't sexist. The Sexism filtering your words because they reach your brain is.