That's a weird way of saying "lack of competition". As others have mentioned, why should Epic Games bother supporting Linux?
Considering that I'm gaming on Linux, the number of competitors is pretty small and close to zero, I'm not sure why I should be forced to switch operating systems to support the "better platform".
I say this as someone who's been running Vortex/Skyrim modding on Linux years before there was official support for it and I'm kind of shocked honestly to hear that people are cheering for something I did so long ago (5 years to be precise) I hardly remember the time doing it.