I'm a Windows user. I have very occasionally and for very specific reasons installed Linux (mostly in a VM). But there is a world of difference between spending a little time to installing a free operating system, and in forking out a significant amount of cash to buy an operating system for test purposes.

Expecting people (who are trying to make your life easier) to pay for and maintain systems that they otherwise have no use for and no interest in is simply unreasonable.

As for "Why should it have had non-portable dependencies in the first place?". That sounds exactly like one of our testers (now left) who used to get angry with us for "putting bugs in". We didn't "put the bugs in" and people don't intentionally write code that is not portable. But there is a lot of work and a great deal of skill required to consistently write portable code - about the same measure of both that is required to write bug free code. Do you write bug free code first time every time? I know a place where you can get a job if you can, just name your price.