Isn't it even simpler? There are no (or almost no) questions in the training data that the correct answer to is "I don't know".

Once you train model within specific domain and add to training data out of domain questions or unresolvable questions within domain things will improve.

The question is, is this desirable if most of users grew to love sycophantic confident confabulators.

> The question is, is this desirable if most of users grew to love sycophantic confident confabulators.

Most people love human versions of the wonderfully phrased same, so no surprise there.