A bit baffling, IMO, the focus on GIL over actual python performance, particularly when you had so many examples of language virtual machines improving performance in that era. So many lost opportunities.
They don't want to throw away the extensions and ecosystem. Let's say Jython, or some other modern implementation became the successor. All of the extensions need to be updated (frequently rewritten) to be compatible with and exploit the characteristics of that platform.
It was expected that extension maintainers would respond negatively to this. In many cases it presents a decision: do I port this to the new platform, or move away from Python completely? You have to remember, the impactful decisions leading us down this path were closer to 2008 than today when dropping Python or making it the second option to help people migrate, would have been viable for a lot of these extensions. There was also a lot of potential for people to follow a fork of the traditional CPython interpreter.
There were no great options because there are many variables to consider. Perf is only one of them. Pushing ahead only on perf is hard when it's unclear if it'll actually impact people in the way they think it will when they can't characterize their actual perf problem beyond "GIL bad".
