Bad readers take things too literally-- or else they try to make something into a wild allegory about something else. They are literal-minded when they should be thinking of figurative language, but they also don't realize it when the poem is naming something very basic.
According to one critic, the "cuatro palomas" of a certain Lorca poem are the four gospels. Why? because there are four of them. Nothing else in the poem justifies that, but everything must be made into a symbol of something else.
So symbol-mongering and literal-mindedness are not opposites: they are both the same mentality, with the same inability to distinguish between the literal and the metaphorical.
I had to order the book about the "hechos reales." I hope a good article can come out of it. I reject the idea that "Paca la Coja" from the province of Almería is the "real bride" of Bodas de sangre. I don't even see it as Lorca transforming some sordid reality into poetry. That's a pretty vulgar theory of literature. It would be like talking about Wallace Stevens's "real blackbirds."
Banally, yes, writers do take things from what they know, experience, and think about, but they are creators of fictions.