Assuming that local user access is simply impossible is a problem. But assuming that local user access means you're already fucked can be pretty damn honest. And sysadmins are the people who will know this the best.
Yes. If somebody can login to a machine which they shouldn’t, local exploits are least of our concerns, because this means we have bigger failures in many layers up to that point.
> It is already used in the most critical applications that require levels of assurance only seL4 can provide.
This sounds to me like embedded controĺ systems (airplanes, life support, etc.), not production servers for everyday internet services.
seL4 isn't exactly an everyday pull from a security toolkit though? It's like an entire paradigm. You build a business around the fact that you use seL4, you don't pull it off the shelf for an internet server.
In order to make a pie from scratch you must first create the universe. That's seL4.
