> It sounds a bit like Erlang/OTP's "let it crash" philosophy.

Which was based partly on ideas from Tandem Computers' NonStop / Guardian. Hardware and software were fail-fast i.e. they would work correctly or stop, so they couldn't corrupt data. If there was a problem, the whole processor / process would be stopped, and a backup took over, which seems somewhat similar to the "supervisor" tasks in hubris.

Quite a bit of a different use cases - an embedded os for microcontrollers vs large OLTP applications. They both could be considered "mission critical", at least for the people who own/make money with them.