I appreciate the skepticism, but that's a very fixed mindset. People can absolutely change and I've seen it hundreds of times.

It certainly can take a "come to Jesus" moment like you find out your team hates you, you get fired, a wave of employees quit on you, etc, but people can absolutely change when they decide to.

Character is absolutely important, and it does predispose one to being a better manager, but you can become a good manager later in life.

Unfortunately, as we discuss in the article (I wrote it), the incentives aren't always there, nor are the positive examples of what to do.