Please don't use "guys" this way. This is not PC nitpicking, It's important. "People" or "folks" may not have the ring you're after, but too bad.
This is double if the person you're correcting doesn't think what they're doing is "wrong".
I don't give that privilege to others and I don't expect anybody else to.
I say guys because my developers and analysts and quality managers are all men. The only women I work with are two secretaries, and they're not even in my department.
What's too bad, friend, is that you have deluded yourself into believing you have the right of way over another person, for any reason whatsoever.
Bless your heart!
Please take your SJW-ism somewhere else. This is HN.
1.1 guys People of either sex.