I'm not really seeing the corollary between Windows and Python in regards to new versions and the requiredness thereof. Windows is proprietary and has a cost, and customers of it have a business relationship with Microsoft. Python, by contrast, is free and libre, and is offered with no warranty implied. If the lack of support for Python 2 is proving to be an inconvenience for you and you won't upgrade to Python 3 for whatever reason, well then, all the source is available, and you can do the needful. Hell, you can even build, release, and distribute your own fork of Python 2 that gets continued updates. None of these options are available with Windows.