Genuinely curious (I don't know all that much about these things): To what extent does the SQLite model incentivize poor documentation since that would drive use of paid support services?

For what it's worth, SQLite's documentation is one of the best among all software I've ever used. It's clear, detailed, well-organized, and everything is documented.

If the documentation is poor, the implementers won't even be able to get it to a point where they would consider paying for consulting.

I mean poor enough that its easy to get set up but more complex usage ends up requiring support services, by which lock in has started occuring.