The problem with "feedback" is that it's usually one-directional and doesn't foster discourse. And this article basically says the opposite - just tell someone their weakness flat out. That's very callous.

Feedback generally works best when it also provides a solution and preferably is outcome-orientated and not a judgement about personal character or performance.

If you really feel an urgent need to tell someone what you think of them, don't think of it as "giving feedback" but as "a teaching moment" and show them a different way.