Not a helpful comment when this person has suggested it has negatively affected their life and is looking to change.
You can and should always work on yourself. Focusing on self-awareness and feedback from others helps a lot to adjust your behavior to make others around you feel loved and supported, which in turn will only make your life way easier because people will like you and want to see you succeed. It's a normal part of maturing. Just because it's hard doesn't mean it's not the right thing to do.
I agree that my comments could be harmful if it was the only one, but there needs to be balance in advice.
I assume this person is "successful", may be that's the faulty assumption.