I really don't know where this is coming from. The only people I hear talking about a 2v3 divide are my Javascript developer friends, who are saying that as outside observers.
As a Python dev, I (and all the other Python devs I know) were just waiting for (and helping) libraries to start working with 3 before we can switch over. These days, all my new projects are in 3, 2 is pretty much for legacy code only.