I know what he was trying to say, but I don't think that's actually what he said. What he should have said is that you should pick an interface that suits your

I know what he was trying to say, but I don't think that's actually what he said. What he should have said is that you should pick an interface that suits your computation. The problem was not that the interface was too simple, but that it didn't fit the computation. One can easily imagine an object-oriented interface for the same wrapper computation that also hides the true nature of the computation.