I don't agree with 1. I use that feature a lot, I write a base class which my students must subclass to their liking, but they still expect that help(TheirClass) will give them the documentation they need.

I agree that in _some_ cases it is not helpful (but even when the base is abstract, it might be helpful). How about: we keep the current behavior, but make it clear that the docstring applies to a superclass? It might be subtle, as just changing the first line of help() output (currently it says "Help on class Derived in module ...", change it to "Help on class Base in module ..."), or write a longer message such as "Documentation for Derived not found, showing the documentation for Base". But just removing it in all cases is really a wrong thing to do.