The issue is that there are a lot of system administrators with “15 years experience in Linux” that have no real experience in Linux.
Reminds me of this guy I helped a few years ago. His name was Bob, and he was a sysadmin at a predominantly Windows company. The software I was supporting, however, only ran on Linux. So since Bob had been a UNIX admin back in the 80s they picked him to install the software.
But it had been 30 years since he ever touched a CLI. Every time I got on a call with him, I'd have to give him every keystroke one by one, all while listening to him complain about how much he hated it. After three or four calls I just gave up and used the screenshare to do everything myself.
AFAIK he's still the only Linux "sysadmin" there.