The author evidently does not understand how threaded programming works in Python. The reason for the "data races" he describes is that, even with the GIL in Python, you have no control over the order in which different threads execute particular operations that are operating on the same objects, unless you use synchronization primitives like mutexes. Python has never claimed that having the GIL allows you to avoid that.

The Python documentation on threading and the GIL [1] makes it clear that the reason for the GIL is to make operations on Python objects inside the interpreter thread-safe, by ensuring that the C structures that store the states of Python objects can only be mutated by one thread at a time. All of those C-level operations happen "inside" a single bytecode. Python operations that require multiple bytecodes do not have any of the same guarantees.

[1] https://docs.python.org/3/c-api/init.html#thread-state-and-t...