Once you know how to code really well shouldn't you be in a position to manage developers and ensure that they're doing a really good job at writing code? You'll be able to help them tackle bigger problems, work on more ambitious solutions, than they could if you're stuck cranking out code with no time to assist.

If it's your job to magnify the output of your developers, when you know intimately how to do their job, you can get spectacular results.

Non-technical managers can't do this, they don't have the depth and insight to help shape their team the same way a developer does.