Are arcade cabinets really PC? As far as i know they use their own modified chip or gpu just like how consoles have their own specialized cpu and gpu. If what you say is true then why no GGXrd on PC? Not a big market on it? How come no tekken game on PC?
Guilty Gear Xrd runs on RingEdge 2: http://www.system16.com/hardware.php?id=982
It's basically just a PC, and the game runs on Unreal Engine 3. It would be trivial to make an actual PC release, but the reason why there isn't one is probably because they're not interested or they don't have the resources to put towards the QA and marketing for another platform. It's a niche game after all. Having to do testing and support for a wider range of possible setups on the PC is also not the same as supporting a single specific configuration for an arcade release.
In the past people have been able to reverse engineer and hack out the DRM from some arcade software to run on PCs.