The paper analogy doesn't really fit. Having a limitless scope doesn't prevent anything from being built on it.
The metaphor of a pool works better. If you're developing a comment/post agnostic app, which pool do you choose? And if those pools become even more and more subdivided which mini-hot-tub do you pick then?
Plus, if you're a person who owns stake in the network, you'd be disenfranchised from your own influence unless you were willing to double your curation "workload."