No amount of vitriolic words or technical nitpicking will change the fact that there will be more work to be done, both by application developers enforcing policies and by extensions having to oblige them.

> the current fashion in programming languages is to allow an implementation to do anything... I think life could, in fact, get easier.

Easier for whom? Not for the lib developer, who will have to follow more rules ("import" mechanisms already have some, by the way), nor for the runtime developer, who will have to enforce them. Easier for the final user who executes runtime and lib? Maybe, but then you cannot expect any serious traction from developers (whose life you're making harder). Trade-offs and all that.