If you have several large software products rolled out and churning away at hundreds of customer sites, moving from Python 2.x all the way to 2.7 alone is a slow and tedious process of tests and deliberations. And we're still not talking about going all the way to 3.x which breaks things in even more new and exciting ways.
So scoff all you want, but Python 2.x isn't going away that soon.
If moving to a 2010 version of your programming language is slow and tedious you're doing something very wrong.
In the Java world (conservative and slow-moving) JRE 7 (2011) is considered the absolute minimum, and if you're not targeting JRE 8 (2014) you have to have a very good reason.
I think this is an inherent problem with dynamically typed languages. There are no reliable refactoring tools so even the slightest non compatible change can be lurking anywhere for years. And with things like meta programming, monkey patching and relying on private members, even changes that are supposed to be backwards compatible might end up to not be.
Try to move with half a million LoC of dynamically typed code with a handful of developers with not a single update breaking for any customer and I will be impressed.
So scoff all you want, but Python 2.x isn't going away that soon.