However, there should be no 'default' python. People should go get 2 or 3 as needed. If there is a default it should be the latest version.
Actually, the situation is very damaging for Python, because Python has momentum _now_ and many new users are confused and put off by the fact that they cannot use the latest Python version for their projects.
Granted, these issues affect mainly web development, which may not be the main concern of a Linux distribution.
There's a big difference between breaking and deprecation.
I imagine that someone could easily be packaging 10 Python apps or libraries. He can't be upgrading all that code to Python 3 as it is not always a trivial task and would require a lot of work and constant patching if the developing team keeps working with Python 2.X
But overall, I think this is a good way to push developers to upgrade or at least prepare more to move to Python 3.
So package maintainers don't need to rewrite upstream code if it's not compatible with Python 3; they just need to update dependencies and set paths to point to the /usr/bin/python2 binary.
This seems more like somebody trying to evangelize for Python 3 and against Python 2, by purposely breaking a lot of old software, and quite antithetical to the Robustness Principle that I would expect most good software to at least attempt to shoot for.
Hopefully other distros will take a more conservative path. Python 2.x is going to be around for a long, long time.