[Volundr]

It's an interesting bit of context. I also grew up with guys as a generic plural, but it's not really generic, rather it's a mixed group plural. It would feel just as natural to say "the people I date", as "the women I date", but never "the guys I date.

Even that's a weak rule though. For example if a girls soccer team performed really well you might hear someone say "those guys really gave it their all today" (though I'd say this usage is mostly dead, I don't think I've heard it this way in a long time), but never "THE guys really gave it their all today".

I'm sure some linguists have studied this and have a term for this kind of thing.