There were also several large business sectors that ran almost exclusively Sun hardware. Like the wireless industry 10 years ago. The first project I worked on at scale had to run on Solaris or they wouldn't talk to you.

And our log files had to be localized, which while Java is not perfect, few if any string interpolation libraries match it for being able to deal with written languages that have a different sentence structure than English. It was hard work and one of my coworkers had to invent a new linter to detect unlocalized text in our code, but I couldn't imagine fulfilling those requirements in another language.