> And unfortunately, the design decisions made for those operators don't extend to anything else written in the language.

Yes, it applies to a number of built in functions and other operators beyond the mathematical ones.

And there's no reason they can't to even non-built-ins. When you implement a method or function, you can adopt a similar special-method-based protocol for it's arguments, and define the appropriate special methods (monkey patching existing classes, if necessary) for the acceptable types.

> If "strong typing" is to mean something about the language, it should it should apply to more than a handful of built-in operators.

I suppose there is a difference between a language with a weakly typed core (where you cannot avoid the risks of weak typing without isolating the core), one with a strongly typed core that doesn't force user code to be strongly typed (where Python sits), and one that forced strong typing (which probably had to be static, as well).