Oh, I see what you mean. I think you're linking this comment to the original post more strongly than I meant. By calling it "tangential" I meant to distance it a bit, since it wasn't an argument for particular tactics towards getting diversity (e.g. "having norms that prevent certain views from being expressed", as you put it). Rather, it was an explication of why diversity might be desirable to have.

I take the opposite of diversity to be something like unanimity. A reason to seek diverse views rather than unanimous ones is that diverse views carry more information. They've got a bunch of wrong ideas too, of course; but their errors are less correlated than those of a unanimous population.