Why has García Márquez’s magical realism cemented its place on American bookshelves and syllabuses while Vargas Llosa’s gritty masterpieces are neglected? Vargas Llosa’s best books are harder to read than García Márquez’s. He’s less sentimental, dirtier, raunchier, angrier. “One Hundred Years of Solitude” looks like a Hallmark card next to “Conversation in the Cathedral.” You might be fired for assigning Vargas Llosa in high school English. And Vargas Llosa has published so many novels — 18 in all — that the tours de force can get lost among the mediocrities. His buttoned-up public demeanor hasn’t helped. “Gabo” was not only a tremendous writer; he was an expert showman who once worked in advertising and cannily played up his Caribbean exoticism for foreign audiences. When the two fell out in the 1970s, many intellectuals leaned left toward García Márquez, while Vargas Llosa was shunned.