Inertia and/or lack of knowledge, likely. There are colleges in India which even today use Turbo C (maybe v2.0) as the tool to teach C, for example, even though

Inertia and/or lack of knowledge, likely. There are colleges in India which even today use Turbo C (maybe v2.0) as the tool to teach C, for example, even though there are things like Bloodshed Dev-C++ and GCC - GCC even on Windows via probably Cygwin, MinGW, or WSL (not checked if GCC works on all those, think I have seen it on 1 or 2 of them).