We all know what the bad student does. He takes literally what he should read metaphorically; he is "plodding" and unimaginative. She answers too quickly in class, with the "easy" version of the answer, as though you had asked a stupid question with a super obvious answer. When asked not to be so literal minded, however, the student will come up with super-convoluted, overly metaphorical answers with no basis in the text. The bad student is literal when he should be metaphorical and metaphorical when she should be literal.
A bad critic will do the same. If there are four doves in a Lorca poem, those represent the four gospels. Why? We have no idea. These far-fetched readings go along with a very limited and literal minded approach, rooted always in biography and authorial intentionality. The bad critic needs to reverse his approach, but how to do this? Isn't knowing when to look accurately at the basic facts in front on you, and when to interpret a bit more, the very basis of being an intelligent critic? We can't just tell her to "be intelligent about it." (Obviously that's not the only definition of intelligence, but it is one of them. You can seem "brilliant" precisely by going for a lot of far-fetched stuff, if you know how to play the game.)
There ought to be a way of formulating this as a hermeneutic rule.