That whole GBM debacle was simply their masking of a deeper problem. They can't interoperate with the kernel properly because their driver module is not GPL com

That whole GBM debacle was simply their masking of a deeper problem. They can't interoperate with the kernel properly because their driver module is not GPL compliant. And proper Wayland support relies on a lot of kernel (DRM) functionality. They have to do convoluted dance workarounds to address the above. Basically, Nvidia will never work really well on Wayland until their kernel driver is upstreamed. This year they finally decided to open source their kernel module. But it's still some road for them to get to upstreaming.