Quentin Tarantino is a previous winner in this category, so maybe they wanted to spread the wealth this year. I mean, all of the major winners were first time winners and, with the exception of Jeff Bridges, first time nominees. Anyway, I'm sure that Tarantino will eventually be an Oscar winner once again, and probably in the directing category.
"Young men make wars and the virtues of war are the virtues of young men: courage and hope for the future. Then old men make the peace, and the vices of peace are the vices of old men: mistrust and caution." -- Alec Guinness (Lawrence of Arabia)