Directness or rudeness

In this post, I’d like to discuss an important topic. I’ve often heard phrases like "I’m just being blunt," "I just want to be honest with you," and "Don't take this the wrong way, but..." followed by something rude. For example: "I don't think you had any friends in school," "You’re terrible at conversation," and so on. That isn't bluntness; it’s an insult. It would be one thing if I’d heard this just once, but it’s happened many times. To avoid any misunderstanding, I want to clarify that I never did anything wrong to the people who said these things to me; generally, I always try to be polite.

Please share your thoughts on this topic.