Ultimately security is incompatible with backwards compatibility. All OSes in prod today need to be rebuilt from the ground up to be secure for the next century. That means throwing out a lot of code too. It's the cost to pay.
It kind of sounds like you're advocating the type of security where the computer is secure against its owner, can't be programmed by its owner, doesn't support modifications to the OS, and so on. Is that right, or so you envision a highly secure system that can be controlled by its owner?
> All OSes in prod today need to be rebuilt from the ground up to be secure for the next century
Qubes OS solves this with hardware virtualization, which is really fast and secure.
> That means throwing out a lot of code too. It's the cost to pay.
And likely, upsetting power users who want to run with all the safeties off.