The reason this approach is so much slower than some of the other 'fast' pythons out there that have come before is that they are making sure you don't have to rewrite a bunch of existing libraries.

That is the problem with all the fast python implementations that have come before. Yes, they're faster than 'normal' python in many benchmarks, but they don't support the entire current ecosystem. For example Instagram's python implementation is blazing fast for doing exactly what Instagram is using python for, but is probably completely useless for what I'm using python for.