I fully expect that new layers will someday allow us to facilitate higher transaction volumes, though I'm concerned about the current state of the network and the fact that there are no concrete timelines for the rollout of aforementioned high volume networks.

As for reasoning behind why users will still need to settle on-chain even with the existence of high volume networks, see these posts:

http://sourceforge.net/p/bitcoin/mailman/message/34119233/

http://sourceforge.net/p/bitcoin/mailman/message/34113067/

Point being, the scalability proposals that are currently being developed are not magic bullets and still require the occasional on-chain settlement. Larger blocks will be necessary with or without the actual scalability enhancements.

- Jameson

On Thu, Jul 30, 2015 at 12:36 PM, Bryan Bishop <kanzure@gmail.com> wrote:
On Thu, Jul 30, 2015 at 11:23 AM, Jameson Lopp via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:
Stated differently, if the cost or contention of using the network rises to the point of excluding the average user from making transactions, then they probably aren't going to care that they can run a node at trivial cost.

That's an interesting claim; so suppose you're living in a future where transactions are summarizing millions or billions of other daily transactions, possibly with merkle hashes. You think that because a user can't individually broadcast his own personal transaction, that the user would not be interested in verifying the presence of a summarizing transaction in the blockchain? I'm just curious if you could elaborate on this effect. Why would I need to see my individual transactions on the network, but not see aggregate transactions that include my own?