This comment demonstrates a tremendous amount of naivete about the Cpython runtime. After PyObject itself, the GIL mutex is probably the next most important data structure in the entire codebase. It's not "someone not being bothered to write thread-safe software." It's not something you can hide behind a flag. It's central to the entire cpython data model and any library which relies on releasing the GIL.

The closest anyone has come to removing the GIL is the Gilectomy project by Larry Hastings, and it's unlikely to ever be upstreamed unless it could be somehow made to work with libraries that rely on assumptions about GIL mechanics (eg numpy).