The idea has some merit. However examples of both good and bad questions should be readily available to the novices as examples of both how, and how not, to post questions.

The poorly posted questions quickly get replies indicating what their deficiencies are and frequently pointing the OP at site material that can aid in generating a cogent question.

On balance I think current policy should stand. A public reprimand is likely a better behaviour modifier than a quiet word in the ear, and is surely a better lesson to others.