I’d go even farther than that: I’d argue that those signs are an admission of incompetence by the engineer who approved their installation.
I’m becoming more and more convinced that the path towards improving the situation is to directly target the engineers themselves by going after the license of those who fail to design streets appropriately for all users. Even if they follow established government guidelines or industry best practices, that shouldn’t be a defense because the guidelines and best practices are wrong to begin with.