I question why we accept someone resigning after making a big mistake. Unless it's malice, or the fault truly is entirely on that person, what good would resig

I question why we accept someone resigning after making a big mistake. Unless it's malice, or the fault truly is entirely on that person, what good would resigning do? Rowley admitted he fucked up, badly, he admitted on several layers what must be changed. How he must change. How the org must change. How the way things are presently is not good enough. Made an extremely deep dive into what happened. And now he's leaving??? Someone who royalty messes up, would not want to mess up on the same issue twice. So all that experience is now worthless and doesn't benefit Digicert in the slightest.