Patrice points out that "no one was trying to ban any speech here" and continues,
Federal trademark protection flows from the congressional power to regulate interstate commerce, and in light of the broad grant of power the Framers gave the government here, it’s entirely reasonable for the government to impose limits on what marks it gives the imprimatur of nationwide recognition, in the interest of regulating the market. This isn’t banning someone from expressing a disparaging view. It’s not even banning someone from making money off a disparaging view. The statute barred the federal government from inserting itself into a potential dispute between someone trying to make money off a racial slur and someone trying to make bootleg products to make money off that same racial slur. And, as already discussed, it doesn’t even stop someone from suing the bootlegger.Such limits stop being "entirely reasonable" when they are based on viewpoint. In fact, a long line of precedent forbids government to impose such viewpoint-based restrictions, even when government was under no Constitutional obligation to provide the service under consideration in the first place.