@dwr
1. A protocol allows for a bunch of apps to reasonably interoperate in a way that's more useful than rolling your own, i.e. you benefit from the liquidity or network effect
2. Crypto protocols are able to successfully capture value at the protocol layer as a result of apps / users using the protocol. Successful capture at the protocol level means the protocol has a independent funding source to decide what the protocol should optimize for.
HTTP and SMTP do not have value capture. All value accrues to the companies building on it. The biggest companies de facto control the protocols.