Agreed. I'm approaching this thinking that the exit points can be backbone providers and we could build simple software to enable users to pay for the bandwidth (to the exit) that they've utilized. Connectivity within the network would be free and we could even place peering points at the exit to reduce outbound bandwidth.
Then it just becomes a question of incentivizing users by consistently driving down costs (in theory) to promote density of nodes.
Yes, this could be an intermediary state between a full–blown mesh network which everything is fully peered, and a fully centralised network such as today's Internet. It all depends on everybody carrying their own weight, though, and of all, that seems to be the farthest away concept so far. Phones and other mobile devices are consuming an increasingly sizeable chunk of the pool and those devices are barely able to connect and to their work, much less work for others due to battery restrictions, which are ultimately bound by the laws of physics.
This is also the reason Aether will most probably never have a mobile version. Not until they finally make nuclear fusion work, and compact it enough to make batteries with it!
Then it just becomes a question of incentivizing users by consistently driving down costs (in theory) to promote density of nodes.