Classes in scripting languages

I'm new to weakly typed high level scripting languages and such. Both JavaScript and Python seem to support objects which are like.. not really objects. But lumps you sort of deform however you like at run time by just appending shit willy nilly. How is this a good thing? When is this a good thing? Even inheritance get messy as all hell. Is there even a situation where this is a good thing besides inheritance?

>>7

Don't use this stupid "duck typing" term. A good reason not to is that dynamic typing existed more than 40 years before the stupid term, which only dates back to 2000. Nobody felt the need to call it duck typing, so why start now.