I stayed away from the management track but friends who didn't tell me one of the metrics they are graded on is retention, i.e. if your reports leave at a more than average rate you will have a problem.

Every engineer in a given department knows who the good and bad managers are. If you don't care about your engineers' development, you won't be able to keep good engineers on your team as they will transfer internally. Engineers also talk to directors and make sure they know who the good managers are. There's really no upside to treating your engineers like crap.