How did the medical advice guideline get to be the way that it is?

The speed of the Reference Desk.

The presence of novice and anonymous editors.

Why must we remove the question; why can't we just box it up or add a warning?

Why can't we just remove any answers that are medical advice?

Why do we have to remove the question without discussing it first? - we have other exceptions to the preferred consensus-first approach.

Can't people just lie about their intentions?