I agree that we should not be ashamed from our mistakes, we should sincerely know our mistakes and know our filthy dirty side to learn from it. But our objective is not imperfection. We shouldn´t deny it or we will never learn anything, and we will be hypocrite persons that are corrupt but don´t want to know it. People like to be bad having the illusion that they are good. People protect themselves from their own corruption with hypocrisy.
If you will do a bad thing at least do it knowing that it is bad, but people are too coward to do this.