Virtually no anticheat worked on Linux just a few years ago except maybe Valve and Blizzard in-house solutions. Games that are out and already committed to a specific anticheat can't do much but to wait, so it is not really on them. Changing the anticheat solution mid-way on a released game would piss off so many people you can't imagine. On a brand new game though, I would agree that this should be considered.