People have to stop saying this. Google isn't so blind as to think every product's sole purpose is to drive pageviews.

I'm speculating just as much as you are, but I don't think it's unreasonable to guess that a big part of Google+ is to drive usage of its other products. Once people start sharing directions, collaborating on documents, and so on G+ will be there to introduce users to one product after another. Sure, social ads may/will be important, but saying "what Google will care about is pageviews" is simplifying it immensely.