Have you seen Nix? It can be used in this way, and its configuration language is relatively good.
Containers are great if you've got racks full of actual, physical servers and want to use them efficiently. Most people don't have that problem, though.
Can you post a link to how nix handles resource permissioning?
When someone could solve something that didn't work for me, they did. When no one could or didn't have time, they kept silent or politely tried to help me find the solution myself. And everything absolutely for free!
Sucks to hear about the negativity. For what it's worth, I've gotten a handful of pull requests accepted with positive experience each time.
This was somewhere in the second half of last year.