Yeah... good luck taking a newer version of Python an compiling it on Visual Studio 2012. I had to jump through hoops even to get 2.7 to compile and wound up abandoning it because it caused problems down the line with ctypes.
C99 support was added in VS2015 to the extent required by C++14, similarly C11 support was added in 2017 to the extent required by C++17.
You don't work in the enterprise domain which is VS’s core market, do you?
Usually it takes one year to upgrade to a new version, after its release.
We are already playing with 2017 for next year upgrade cycle.