“But I'm just being honest."

That's right. You're just being honest. You are not being compassionate, or considerate, or thoughtful, or lovinf, or polite, or pleasent. Just honest.

There are times when someone has to deliver the unpleasant truth. There may even be times when that person is the, "just being honest" fanatic. But so much more often, unvarnished honesty is unnecessar, unkind and unwarranted, and a little thought put into delivery of the message would go such a long way towards making it valuable and constructive feedback rather than a shattering blow that can only be forgiven, not forgotten.