if you call everyone dude and a transfem person gets mad about it, don't get defensive. just say like "sorry, i won't do it again" and don't argue "actually it's gender neutral" or "i call everyone dude". even if you do, i guarantee she's heard that argument from someone who very much does not call people they see as women dude. i certainly have
same goes double for the word guy.
i don't think you don't need to leave or anything, and i appreciate the genuine apology. i do think it's important to note that a lot of times issues with microaggressions are difficult to parse when you're on the other end, and as mentioned many people see themselves as using bro/dude as gender neutral but very much do not. linguistic descriptivism isn't a bad way of looking at it but i think it's important to try and put yourself in the shoes of the group actually being discussed here and imagine what it looks like from their perspective. very difficult to know what camp someone falls into when talking about it online