Object orientation is a Good Thing (tm) because it enforces information hiding. You only should care about the interface an object presents to your client code, not the internal object implementation. Hiding the guts through encapsulation and access control has the added benefit of not letting you shoot yourself in the foot. Even if you'd like to, you can't reach in and wreak havoc.

At least in languages like Java. Sure, you can ultimately write any code in assembly, but the benefit of catching oft-recurring errors at compile time is gone.