"own up to your mistakes"
That right there is one of the hardest things to do. If you look at the history of humans, I'm sure that you will find many, many more instances of people covering up their goofs rather than admitting them and working on fixing the issue.
I think it is a case of misplaced pride. We act as if we are perfect, we strive to impose that image on people around us, and anything that might tar that image must be suppressed.
Before the Internet, you could maintain the illusion because nobody who didn't know you had any way of finding out. That time is over now. Maybe our species is going to learn ?