Amazon management is bad at their jobs

There is no other way to say it: Amazon management is bad at their jobs, but they will not be corrected because the company is overall doing well. Amazon teaches its managers to be  disinterested in people development since they feel everybody can be immediately replaced. This leads directly to poor team morale. The attrition is appalling. For example, I started the same day  with 15 of my colleagues and there was only three of us left after twelve months. This is consistent with what I've seen in other departments too. The main reason for the attrition is the lack of opportunity to move up since the promotions process appears to be rigged and doesn't reward the people who actually did the best job. Moreover, they hire externally for managers and senior engineers since they can't actually let people honestly grow in their career. There are a few other negative things that I find personally wrong, however these people development problems are the most pervasive as far as I can tell.