There is a huge difference between thinking bad thoughts and expressing or acting on them.

You can be as racist as you want in your own head. No one is stopping that. You can express those racist thoughts all you want on your own property.

But you have absolutely no right to express or act on those racist thoughts on someone else's property.

People who are paralyzed and unable to speak aren't spreading hate in video games, so it's pretty pointless to hold them up as a counterexample. I know my grandparents probably have a lot of racist thoughts but unless they're unloading them at the Thanksgiving dinner table I'm not telling my grandmother to shut her mouth.

It's not like they can say or do anything racist, so the net effect is the same as if they were not racist.