Well, thread safety is exactly about these cases of "well, it's hardly ever a problem". Real life bugs have come from misapplication of correct parameters for

Well, thread safety is exactly about these cases of "well, it's hardly ever a problem". Real life bugs have come from misapplication of correct parameters for memory barriers, even on x86. Python GIL removes a whole class of potential errors. Not that I'm against getting rid of the GIL, but I'm more sceptical that it won't trigger bugs. Though in my opinion python just isn't a good language for large programs for other reasons. But it'd be nice to be able to multithread some 50 line scripts.