Dumbing Down the Titles

One of the more irritating little things in Mexico is the tendency to perform radical surgery on the titles of movies, virtually always making them more anodyne, trite, or, obvious (and sometimes all three at once). Anything that smacks of subtlety or mystery is removed; in its place some bit of inanity or over-literalness is inserted. One good example is No Country for Old Men, which became Sin Lugar para los Débiles, or (roughly) No Space for the Weak, in the Mexican edition (though only with the movie title; the book was translated faithfully). But the best example is The Informant, which turned into El Desinformante in Mexico, which is to say, the exact opposite of the original title. As a result, the pleasant uncertainty about the protagonist's own shady doings, which was clearly a purposeful element of the film's first half, disappears. In addition to undermining the director's intentions, I don't see what would be the reason for the dumbing-down. Do the title translators somehow assume that the Mexican public would be driven away by an indirect title? Is the theory that calling the movie El Informante would have lowered ticket sales? It baffles.