Earlier quoted context omitted.
The data is there in an HTML page. I'm looking at it. I just want to stick ".xml" or ".json" on the end and see the exact same thing in a machine readable form. Whatever complex enterprise data warehousing you are doing to get it in my browser as an HTML page is very impressive, I'm sure. It can be as complicated as you want it to be if you want to offer something more complicated than that. But for the basic use cas…
On your web page you say "I just want the data on your website in a machine readable format. XML, JSON, RDF, CSV, YAML, I don’t particularly give a fuck. ... I don’t want a relationship with you, I just want to have a fiddle with your data." But in your comment you say "The data is there in an HTML page. ... I just want to stick .xml or .json on the end and see the exact same thing in a machine readable form." In the…
It may be necessary to have big complicated APIs some of the time. Great. Mostly, it's not necessary: you have a URI structure, you have pointers between records (hyperlinks), you just need a machine readable representation of the data. HTTP and web architecture already does that. You don't need a special fancy API with things I need to learn and understand.
On reading your clarification: okay. You term what I call "data" as a "query result". Then it's a merely semantic distinction you are drawing. And, I'd suggest, probably an irrelevant one from the perspective of the data consumer. There's a URL for a resource. I want the stuff there. I don't care whether it's in a database or how it's stored. That's just plumbing.