I think there's a different problem. I think a lot of success in hierarchies is based around the willingness and ability to turn a screw. What domain expertis

I think there's a different problem. I think a lot of success in hierarchies is based around the willingness and ability to turn a screw. What domain expertise buys you is a higher intuition on whether or not you should. Sure, you can have a lot of technical managers who suck. You can also have a good experience with a non-technical manager. But day by day, pound for pound, my money is on domain expertise leading to better results. This happily explains why a manager is typically a senior role. Course, there's a lot of ways to screw that up.