Totally agree - the true source of all of the value here is the new incentive to write very simple services with very simple documentation and to make that documentation easily discoverable.

It fills a gap that exists in most service documentation: an easily discoverable page for developers (specifically, those who already know how to use their ecosystem of choice's HTTP APIs) that has a very short list of the service's most fundamental functionality with a simplified specification so they can go and play around with it.