Here's the real Principals of Engineering Management, according to pretty much every middle manager, director, and vp I've ever worked with:
1. Be caviling and pedantic, so you can reinforce your position of petty power.
2. Contribute exactly zero code, infrastructure, etc. Basically, anything that actually provides value to the engineers or the customers, you don't touch.
3. Put at least a couple meetings on the calendar every day of every engineer that they don't need to be at to remind them you rule over their time.
4. Push nebulous "goals", then have very set goals when it comes time to promote/give a pay raise an engineer and then insist they aren't quite there.
5. Put engineers on-call instead of hiring support staff, again to remind the engineer that you own their time, even when they're not at work.
6. Constantly seek updates from engineers, so many in fact that they can't complete the work on time, then promptly blame the engineers for not delivering.
"Managers" are people with business degrees who failed out of anything technical. Real managers are architects and PMs who actually understand the product and the technical lift it takes to actually make things happen. They don't concern themselves with your comings-and-goings, but whether you can get things done or not.