I think the question was if you aren't going to be backwards compatible, why not unshackle yourself completely and design a new language without the GIL and make it as pythonic as possible?
A scripting language that support multi-threading is possible, right? I think TCL does it.
I guess they were happy with breaking backwards compatibility a little bit, not not as much as simply removing the GIL and not adding back any implicit synchronisation at all.
I think this question can only be raised in hindsight. I think nobody suspected the unicode transition to be so slow and painful. As there probably won't be such a big transition evermore, I wouldn't hold my breath for it happening.
A scripting language that support multi-threading is possible, right? I think TCL does it.