Yes, this strong process isolation is one of the design decisions which leads to the ultimate success of Erlang/OTP as a telecom platform. Joe Armstrong's thesi

Yes, this strong process isolation is one of the design decisions which leads to the ultimate success of Erlang/OTP as a telecom platform. Joe Armstrong's thesis has explicit explanation why JVM is not suitable for telecom-grade reliability (no matter what sales people would tell you). Another principal design decision, which complements share-nothing architecture, is a pure functional language with single "assignment". This greatly simplified runtime and VM itself which leads to more controlled and predictable behavior, suitable for soft-realtime systems. The concept of drivers is another one, but it is irrelevant to this discussion.