I've been using "industrial" machines that cost $150,000 or more for almost 20 years. They all run from a Windows PC.
I doubt that there are any real commercially available "industrial " machines running Linux CNC.

LinuxCNC is a viable alternative. But the LinuxCNC guys need to stop knocking Mach3 every chance they get.
Mach3 users probably outnumber LinuxCNC users by at least 20:1. So Mach3 can't be all that bad.