Unfortunately it's pretty much impossible to support Nvidia on Linux unless you have a large enough team to test each of their GPUs individually and find workarounds for all of the bugs. Their Linux drivers are really bad.
The bigger projects have been able do that, but if it's a relatively new project with only a handful of people working on it, and it's not used on the steam deck, there's basically no chance it'll support Nvidia.
Allowing bad actors to advertise themselves is highlighting them. Banning them and deleting their communities is the opposite of highlighting them.