>progress
Guido's a shit designer but everyone knows that and bought into it when they bought into Python. For him to break compatibility just to layer on some new shit design though, that's not what everyone bought into. Nobody likes completely pointless bitrot, and that's what Python 3 represents: some jerk who is not even your boss woke up on the wrong side of the bed one day so you now need to revisit and rewrite your Python2 code.
>progress
Meanwhile, some libraries are broken for OCaml right now because the latest version made strings immutable, but A) this isn't a totally pointless change, it's a very good one, B) OCaml is a statically typed language where the compiler assists the programmer enormously in performing the kinds of changes required. If changing critical software is like walking a tightrope, doing it in OCaml is like doing it with a team standing ready to grab your hand and pull you back onto the tightrope if you stumble; doing it in Python is like doing it with a team standing ready to tell you that you're fucking dead after you hit the pavement.