I agree.. people can be dishonest and hurtful while being perfectly polite, just like they can be honest, kind and caring while swearing like sailors. That is the difference that matters. When you ignore that and just look at the form, you get https://en.wikipedia.org/wiki/Perverse_incentive
Here's Linux talking about being straightforward, and why he cannot afford ambiguity:
People need to be a lot more straightforward in their daily dealings with others. The world would be a much better place.