Well, assuming that the amount of "delight" on success is comparable to the amount of annoyance on failure. I suspect that most users won't notice or care if th

Well, assuming that the amount of "delight" on success is comparable to the amount of annoyance on failure. I suspect that most users won't notice or care if the system guesses their gender correctly instead of using gender-neutral terms; but when you misgender a user, they will definitely notice, and they may be extremely annoyed, they may think it's funny and then tell all their friends about how stupid your service is, etc. It doesn't seem like a wise trade-off. Relatedly, deliberately choosing to piss off a subset of users at no major benefit to yourself because you've decided there's not enough of them to affect your bottom line is kind of a dick move, even if it doesn't actually impact your financials directly. That's not a good habit to get into.