Well, I, for one, don't work "almost anywhere", I work with specific servers. I ain't gonna get a new server out of the blue. And if some teams works with the same N servers, they can mandate that the tools are present on all of them.
Plus even on some unknown system, one can quickly copy or download a set of static binaries as our toolset.
So unless someone is a sysadmin for heterogenous networks, or is called to go to random clients and fix unseen before systems, or some corporate mandate prevents them from having their tools installed, there's no reason not to expand beyond standard POSIX userland.