Criticism is easy, but it ultimately leads to misery.
It helps you to believe you are separate from the person you are criticizing, and it excuses you from looking at yourself and the role you play in your own unhappiness.
As long as you can point at someone else as being the problem, you do not have to face the truth about yourself and your relationship with your discontentment.
The only way to transcend this attitude of judgement and the separation it creates is to through compassion and forgiveness, both for others and for yourself.
Compassion and forgiveness are not easy, but they are the path to peace.