And since we all have that one friend or colleague that's always two levels below the stipulated dress code, I also understand the urge to explain it in male / female terms. It's just more specific. If I extend my sympathy to the non-binaries, I could understand that the dividors "Men:" and "Women:" could have been dropped in the explanation. But why is that such a big thing?
I'm not following your second paragraph - it sounds like you're simply saying that the female and male version of the dress code in question have no differences in terms of respect and reasonableness in-context, but surely that's the crux of the disagreement? The point is that I find "wear a short dress and heels" to be more disrespectful than "wear a blazer/slacks/suit". I am making no comment on how those two things are comparable in other contexts, e.g. whether or not they are members of the same dress code by definition. I can't follow how that relates to respect.
Something can be literally true, but in the mean time out of context like this.
The rest is also true, except the author apparently didn't know that the hanging part of a dress and a skirt aren't synonymous (I don't think so anyway). But that has no relevance to what makes it deserving of "rage", as you say, so what are you actually referring to?