The community basically did reject Python 3, at first. Almost nobody used 3.0 / 3.1 / 3.2, to the point where I’ve seen them retconned as beta releases.
Even then though, the core developers made it clear that breaking everyone’s code was the only thing they were willing to do (remember Guido’s big “No 2.8” banner at PyCon?), which left the community with no choice.
Yeah I was in the middle of that and had to keep switching between versions because of how many things were Py2 only or Py3 only. Extra annoying how v3 changed random things like integer division that's mess you up if you forgot.