The embedded and military markets may keep funding them for the foreseeable future but they need a native seL4/Linux if they want to honestly claim they are improving systems' security with their capability model.
Secure–boot virtualization platforms are dime a dozen nowadays.
The current value is that you can take an existing specialist/military device that used distinct physical chips for provable isolation, and consolidate them all onto one chip (lowering cost/power/space), while still saying that you met the security requirements
So its more of an economic argument than that of increasing security
"native seL4/Linux"? seL4 can already host Linux VMs, and there are various methods of running Linux code / binaries without hardware virtualisation.
> but they need a native seL4/Linux if they want to honestly claim they are improving systems' security with their capability model.
Are you using "seL4/Linux" in the style of "GNU/Linux"? Because then it should be "GNU/seL4" - that would describe an OS exposing the GNU core utilities on top of the seL4 kernel. There's no way to mix the Linux kernel with the seL4 kernel, other than using one to run VMs of the other.