[joe_the_user]

It's interesting, because theoretically NLP should be able to "understand" what you mean but in reality I find that even if you parse sentence structure and extract some meaning, you're still at some level hardcoding the possible things that can be queried into the code.

This is a good point.

One thing that I'd claim is that NLP is less useful than you'd think for single queries. I'd just suggest the thought experiment of being able to ask a highly knowledge person one question with no follow-ups. Even someone with a mastery of English and the data probably won't start out with the same idioms and approaches, so you'd have to phrase the question carefully and exactly ... just the way you have to spend a lot of effort writing a SQL or similar query.

If you can interact with such a knowledgeable person, you'd learn their expression style and they'd learn yours - after some interaction one has a very powerful effect. Until then, things are rather limited.