Umm, FUD much? It's a real stretch from Ronacher's (entirely reasonable, from what I can see) complaints to "not for anything you plan to deploy."
The Python 3 support page is full of "this should work in theory, it's very under-tested, almost nobody is using it, don't blame us if you try it anyway and get rooted."
They did everything to warn you short of installing giant neon signs saying "radioactive, don't use in production."