Tim Sweeney is pretty openly against any Linux support for some reason so I think that soured Linux gamers against them.
I have been gaming on Linux for 15 years and it is so much better these days, but we are still not a 1st party target. I get why, but it sucks to be ignored and told to just deal with it forever. I spend as much or more on hardware and software than windows gamers (except for a Windows license I suppose) and I guess I have to vote with my wallet.