Earlier quoted context omitted.
Ok, let's for the sake of argument grant you that a public web app is an official interface (I'm not saying API because it's not a "programming" interface). The implied contract is that humans will continue to be able to use the web app to access the functionality it's intended to provide. Anything in the HTML is an implementation detail, not part of the contract, and is subject to change at any time, so long as the…
> The existence of a public interface usable by humans (a web app) does not in any way imply the existence of a machine-usable protocol for accessing that same functionality. Is that non-implication better for consumers? For people ? If not, why should it exist?
How is that relevant? Putting up a web site does not obligate you to then do more just because it would be even better.