The only expression I have gotten was something like "Why not vim?" and my response was "Because emacs is better, and I can always use evil-mode if I want the vim bindings". Then it gets installed (by me or an admin) and I use it. I can't imagine anyone actually caring, that's pretty petty of them, or lazy based on your other comment about it being too much work for sysadmins.
Why would it be "unprofessional"? It's an editor. I've used it in every job since I left college 20+ years ago.