Criticism and ego's

Why can't people take a bit of criticism? I love it when somebody agrees with me and praises me but I love it even more when somebody disagrees with me. The problem is that our ego steps in and we take all forms of criticism as a personal insult. Instead we should look at was to grow. We would rather sit in a comfort zone of being sheep agreeing with what ever is being said than take a true look at ourselves.

As the Tao saying goes "You have to empty your cup in order to learn" and criticism lets you empty your cup.