‘...the geospatial industry almost completely left behind support for UNIX-like OSes’
It is true that the proprietary GIS vendors have largely abandoned Unix and Unix-like operating systems and continue to do so. However the open source GIS community has embraced all major operating systems with software that runs on Linux, *BSD, Mac OS X, and yes, Windows. This support includes everything from the desktop to the server.
For those of us that prefer to operate in a Un*x environment, that's good news.