Why is Python still frowned upon in Competitive Programming? Like yes it's allowed, but why do we have such a huge stigma against it?

Python only uses one thread at a time (see GIL, global interpreter lock). If you want something fast and can't use numpy for it consider something else than python

@YouAreAPIRate but GIL does not impede multiple processes to run concurrently. I know it's not the same thing, and shared memory is an issue, but in a lot of cases that's good enough to not make a difference from a well threaded application.