[Kalium]

You're right! It's not the fault of the underlying system, it's the fault of the lazy people who work around it trivially.

With that said, some people might consider a system that is much easier to trivially work around than to use properly is one possessed of a wonderful, glorious, bountiful collection of opportunities to improve its design. Such systems are not bad! Not by any means! They just could, perhaps, be somewhat better.

All of that said, I do think a sandbox-based system probably shouldn't allow things inside the sandbox to say "Don't sandbox me bro". That seems less than maximally wise, even if it does also seem super convenient.