Also, if you download and compile Python from python.org, isn't it also just 'python' that you get as your executable? If so arch is just following upstream, and the Python devs should follow their own advice.
Arch doesn't seem to be patching this, though you can see in the PKGBUILD that arch explicitly creates 'python3' as a link to 'python' (with a comment lamenting that this isn't done by default) :
https://git.archlinux.org/svntogit/packages.git/tree/trunk?h...
Arch: ~2010 PEP: ~2011-2012
"in preparation for an eventual change in the default version of Python, Python 2 only scripts should either be updated to be source compatible with Python 3 or else to use python2 in the shebang line."
So it will change eventually. But why rush to break things?