When you consider what it is, it makes sense. It's designed for big companies that want stability, at the cost of being a few OS generations behind the bleeding edge.
Fedora is moving to Python 3, so RHEL (and thus CentOS) will follow, but not for several years.
Python has been a pain on RedHat and derivatives for as long as I can remember. The problem is simply down to the decision to package only a single Python version. On Debian and derivatives you've been able to install distribution packages of multiple python versions (e.g. python2.4 and python2.7) at the same time. You lose all the advantages of a long maintained stable distribution when you have to install a bunch of hand-compiled packages.
Fedora is moving to Python 3, so RHEL (and thus CentOS) will follow, but not for several years.