I was on my 2nd CS year when Slackware 2.0 was released, and we had big boys UNIX on the department, like Aix and DG/UX.
Yet the majority of lab computers were running Windows 95/98.
UNIX was mostly used for the OS, compiler design and distributed computing classes.
Everything else, including graphics programming was on Windows.
(Of course none of this applies to personal computing, where I still don't understand Windows usage beyond the need for niche software).