Code-reuse is not really something that is unique to object oriented development, and it's a shame that people think OO invented code-reuse. It did not. In the wrong hands, OO subclassing actually allows for reuse-avoidance, or even copy-and-paste development in a politically correct format. Furthermore, it is a shame that the philosophy-of-uber-inheritance is so tightly coupled with OO thought that most OO programs instantly grow a tremendous class-hierachy. This too, need not be the case.
Anyhow, OO is fine -- but don't think it's about reuse or maintainability or massive inheritance hierachies or anything like that. It's mostly about state and clean interfaces -- or, at least -- that's how it SHOULD be. The number of real world problems correctly modelled by massive inheritance trees are few and far between.