Since when? All the women I know use "man" or "men" (or informally, "guy"), correctly when referring to a male member of the human species. My wife might say: "my supervisor on this matter is a man." A disproportionate number of men I know incorrectly use "female" when they mean "woman." E.g. one might say "my new boss is female."
> There is no female analog to 'guys'. Males under age 18 -> boys. Males 18-35 -> guys. Males over 35 -> men.
There isn't an obvious alternative to the word "female", as calling a, uhm, "female" of younger age a "woman" can potentially be awkward, so referring to her as a female is simply the next best option. I suspect that it's because of this reality that the word "female" is increasingly more accepted as a safe and normal pronoun.
I'm 30 and I haven't seen this be the case anywhere ever.
I have encountered some people who condescendingly use "boys" when they want to disparage adult men. It's always bugged me even when I was a teenager, although for some reason all the gay men I know use it. I think a similar dynamic exists with women and "girls".
I find myself using "female" occasionally, not to refer to women I would date but because English doesn't have another good word for "feminine humans of an indeterminate age". I occasionally use "chicks" for similar reasons.