Earlier quoted context omitted.
This pattern of phrase is so condescending, and insulting to those who genuinely choose to enter a profession.
Unfortunately, it contains a kernel of truth. I personally met staffers at my alma mater that worked there after failing to advance in their academic career but being too well connected to not have a safety net.
I certainly agree that there are people who teach because they can't do, but I don't think that teaching because you can't do is even part of the kernel of teaching.
As for admins... this is a huge problem right now. They are threatening to destroy the host. But a healthy host does have a trim, effective, and dedicated group of admins.