Alone the fact that you mention RT-11/RSX-11 and VAX OSs shows we were not on the same bubble.
Anyway on VMS most folks would be found using the VMS BASIC compiler, VMS Pascal or Bliss, until Open VMS made it yet another UNIX clone.
My first C compiler used the RatC dialect, let alone having access to a proper K&R C compiler.
By 1992, I already had access to a proper C++ compiler on MS-DOS, and C was history to me, other than scenarios were work was expected to be done in C like some university assignments, even here we were blessed with a plethora of languages between Lisp, Prolog, Smalltalk, ML, C, C++,....