The readme talks about plans for Linux support, but I'm guessing that's no longer on the table after the Epic acquisition? Sweeney is the single most publicly anti-Linux CEO I'm aware of.
The repository was first open sourced 2 years after the acquisition. Nothing has changed about the project’s goals. We are working on the Linux port now. It’s currently our top priority.
Yes actually: plenty of companies don't care where the money comes from, they're happy as long as there's money. Unity, the other big ad- and IAP-peddling game engine company, has pretty good Linux support.
It's weird for a company to explicitly say, "if you use this one operating system you can go F yourself, we don't want your money". (Note: this is not the same as saying "we only officially support Windows at this time, sorry". There's seething hatred in Sweeney's words.)