The worst bosses I've had (a good boss is extremely rare), were promoted because they talked the loudest, and bragged the hardest, and took credit for things that weren't there's. The good bosses just do their job, and give credit to the person who actually did the work. It seems like the qualities that will get you promoted are the qualities that make a bad boss. The egotistical, narcissistic, qualities that get the employee noticed as a "leader" who is worthy of promotion are the qualities that make someone a bad boss. We reward the loud mouth, selfish, morally questionable people with promotions.

And even when upper management is well aware that talent is running from their company, they leave the bad bosses in place. They would rather sacrifice 100 top notch employees than remove one bad boss.