>For example, say you have an object that holds some strings and numbers and it has getters and setters on it. How is that different than a Hash?

Of course this is the most degenerate case of an object, so pointing to this as an counter-argument to OOP seems rather specious. The typical case is that the data being encapsulated is related to each other in some way, and thus having a restricted set of operations on the object can ensure certain invariants are maintained. You cannot duplicate this with just a standard hash.

>and inheritance lets humans do what they love to do - name and categorize things.

You say that like its a bad thing. If humans like to categorize, why shouldn't our programming languages be designed around this tendency?