Re: How many DevOps are we talking about here
I have never knocked at a door, and heard, "Who is they?", it's just wrong!
Because that's a different case of pronoun. You might hear "Who is that?" But even if suffering an identity crisis you wont ask "Who am me?"
"They" for indeterminate or unspecified gender isn't much different from other languages using plural forms for formal address. A French speaker isn't going to think that there must be someone standing beside them because you've asked "comment vous appelez-vous?". And as language work on patterns, it takes the same form of the verb that the normal plural use would. Neither is it a new use, for those who seem to be taking umbrage that it must be some new politically correct conspiracy, and is much less obtrusive than whirling around he/she, (s)he or randomly selecting a gender for each new paragraph.