Just popping in as a professional linguist, since a linguistic item was brought up: ‘Guy’ is amidst a change, where it has historically been gender-specific (that is, marked masculine), but it is changing into a gender-neutral term. The issue with items in this sort of process of change is that some people will see it as exclusive, and others as inclusive.
Therefore, if you’re annoyed that someone uses ‘guy’ to mean everyone, remember that they’re probably using it to actually mean everyone, and (unlike, say, ‘man’) it isn’t the sort of thing where it’s using the masculine as emblematic of everyone—for such speakers, a woman really, honestly, is a guy (whereas she wouldn’t be a man).
For these people, ‘guy’ is actually identical in meaning to ‘people’, except that it’s marked as informal. For many (almost certainly most, and in fact the vast majority) these people, ‘guy’ meaning ‘human male’ isn’t even an option—the idea that ‘guy’ could be that limited is simply bizarre.
And it really does seem that this is a change in progress that’s steadily progressing—if it annoys you now, I’m sorry, but it appears that you’re either going to have to learn to live with it or be annoyed the entire rest of your life. The only languages that don’t change are dead languages—this is simply one manifestation of English being a living language.
And before you say that it’s simply, say, “rude” to use ‘guy’ that way, I’ll just add that if you do, I certainly hope that you’re using that word with its historical meaning of “reflecting characteristics of rurality” rather than the much, much newer meaning of “impolite”.