Exactly. For example, the phrase "bad guy" could apply to a man or a woman. You can't just change that to "bad girl" and keep the meaning. "Bad girl" means something else entirely.
"The one guy" is literally the opposite of uncountable.
Guys, this doesn't have to be so hard. Just check the authorship before commenting about the author! If you get it wrong and someone points it out, say "oops, I should have checked" and it's over.
I debated calling this out and decided against because I knew you all would do it for me.
This, right here, is precisely why this issue is important. We have gendered pronouns that are so ingrained we try to pretend they're not gendered.
"All" is a _shorter_ and more inclusive substitute for "guys".
If you think this isn't important, just replace every occurance of "guys" that you see with "gals". If you're cool with that, good on you, but if you think for one second "oh don't say gals that might piss someone off" then, well, there's the kicker.
I thought using "guys" in a conversation about the use of the word "guys" would be obvious enough to register as tongue-in-cheek. But y'all went and proved me wrong!