>>I think you got it backwards. Databases should record simple facts from which *answers* can be constructed for questions. <<

I do like that better!

>> If "Yes/No" is an answer to some question, the DBMS must allow for it be recorded so that other questions can be answered. It is closure, remember? <<

With that model, a database would already have **all** possible
answers in it before all possible questions are asked. Not possible
even in theory. And the answers are at a different level than the
facts -- the old data and meta data getting mixed together problem,
the need to constantly update the flags when the underlying facts
changes, etc.

Closure in a mathematical system assures that you can compute an
answer from facts, rules, axioms, etc. when presented with a
question.