I've never had manager who hasn't coded ever in his life. WhatI had most of the time was a manager who hasn't coded in a longtime.
The non-technical manager will focus more on the business side and will be easier to manage in many situations, but the problem is that that type fo manager will neglect tasks that are purely linked to technical debt, refactoring etc that don't add new functionality to the system but are still really important.
Plus, threads and processes are essentially the same on unix land – kernel flags will control behavior like shared memory. Which you can still setup manually. Or just use whatever IPC fancies you.
Running on how many CPU cores? Were you writing code for a supercomputing cluster? Otherwise for what kind of system could 10,000 threads possibly be an ok strategy?
Can't wait for 64-core Threadripper to have something similar at home in a little box ;-)
Did he suggest an alternative ?
Putt's Corollary: "Every technical hierarchy, in time, develops a competence inversion." with incompetence being "flushed out of the lower levels" of a technocratic hierarchy, ensuring that technically competent people remain directly in charge of the actual technology while those without technical competence move into management.