Linux is now used more and more by people for gaming purposes, why exclude that? Since they are already running on Android anyways, they already have it ported to the Linux - kernel -.
Well, the kernel isn't really the issue. It's the userspace APIs. As far as those go, we're mainly talking about Vulkan vs. Direct3D. To your point, if it runs on Android, then their engine must've been ported to Vulkan. So, that part part is spot on.
Now, I've heard that 3D Mark actually
does exist for Linux, but it's only available to special individuals. The issue seems to be that they only have a commandline interface working, rather than their normal GUI. Doesn't seem like a big deal to me, but that's what I've heard.
Hopefully, that means we'll
eventually get a Linux version. Perhaps it might be more expensive, if they feel they need to cover the reduced volume.