I've always been told that multiple inheritance is a bad thing, so I've tried to avoid. I didn't dig into why its a problem. I've recently come across a use of multiple inheritance in some python ...

No, you probably don't. Some degree of "IMO" here, but in C++, multiple inheritance is generally an indicator of flawed design. Don't attempt to transliterate Python idioms to C++.

Multiple interface inheritance still allows an object to inherit methods and to behave polymorphically on those methods. The inheriting object just doesn’t get an implementation free ride.