The differentiating feature of Reader for me was that I could have extremely good discussions around various items with a circle of friends and friends-of-friends. I'm not as interested in algorithmically-suggested items, but if somebody whose taste I appreciate has something to say about an item I'd like to be able to discuss that. And that small circle of people has a larger signal-to-noise ratio for me than HN or Reddit comments.

So I think the appeal of a minimal social component in an RSS reader is not adding to the already-unmanageable deluge of information, but to add richness and depth to the existing pool.