Joshua Henkin’s right on the money (emphasis in the following quote’s mine)
The [Blue Flower] won the National Book Critics Circle Award in 1997 [...]. There were a few grumblings at the time (Underworld had been the favorite in some circles), revived more recently when someone (one of the judges? I can’t remember exactly) suggested that The Blue Flower had been a compromise choice and that a smaller, less ambitious novel had won out over a book that swung for the fences. No disrespect meant to Delillo or any of the others, but The Blue Flower, though it comes in at just over 200 pages, is neither small nor unambitious. Would people have said the same thing if the writer had been a man?