Most data center GPUs don't have display outputs and some use exotic connectors (not PCIe x16 slots), making them worth next to nothing as conventional graphics cards.
It's possible these datacenter AI GPUs are built so different from conventional GPUs that they lack required hardware to draw polygons, like ROPs and texture units. Why waste chip engineering time and silicon die space to support applications that a product isn't designed for? Let me remind you that gaming is a small slice of NVidia's balance sheet[1], so it makes sense to not have to use one chip design for everything.
[0] https://www.youtube.com/watch?v=TY4s35uULg4
[1] $4.3 billion out of $57 billion https://nvidianews.nvidia.com/news/nvidia-announces-financia...