If they go down, it will be a really major headache.
It's theoretically possible that the API used could change in a way that old versions of pip can't handle, but a) the API is super simple and there isn't a strong reason to do this and b) doing that would break the ability of old versions of pip to upgrade themselves - that is, for released versions of Python with bundled pip to work - so they're very unlikely to break the existing interface, even if they add a new one.
Still, since PyPI is a free service with no support contracts, and especially because packages hosted on PyPI are uploaded by the individual volunteer authors who have the ability to delete old versions of their own packages, businesses who depend on Python 2 would be well-advised to download/mirror what they need locally to ensure continuity of business.
No, they won't.
> The error here is you think the people doing this even have programmers to port to 3.x or admins with the wherewithal to make sure an older version of pip is used.
What wherewithal does that take? PyPI will just provide the last version of pip that supports Python 2. It takes no extra effort to not install a Python 3 version of pip on Python 2.
> Nobody wants to keep Python 2.x in use or force the Pip maintainers to keep 2.x support.
I'm sure there are people who do want to do the former. And they can, but it has no bearing on the latter.
1. Trivial or easy. Probably started using best 2/3 compatibility practices easily on, or the nature of the code lends itself to 2to3.
2. Not able to switch without effort, but able to be slowly ported to 2/3 with six and the like.
3. Hopelessly intractable. Either too much bad practices in string handling, or tied to a legacy system. No way to port it without risking subtle bugs. Usually this is due to playing fast and loose with string types, even though we have known better since well before python 3.
