Its a perfectly acceptable question. No need for it be treated with derision. Unfortunately I don't have an answer. Maybe there are no distinct secondary sex characteristics on the part of angels to definitely distinguish them as men, e.g. deeper voice, facial hair etc. Maybe they were equidistant between male and female in this regard, but the scripture writers could not process that and defaulted to calling them men, as that was the only appropriate sex in their mind for angels. But this all conjecture. (They are repeatedly described as young men though.) The question is, does the Bible say why they're always men.
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I'm thinking that for angels to be described as young men means they must have appeared very young indeed. In that era the age of maturity was very young already. I've read that many of the apostles could have been in their teens still, and are not described anywhere as young men. The blind leading the blind on this though possibly.
