It's not just the poverty of thought that would put George Weigel on such a list (or keep Archbishop Chaput off the list only through a technicality). That's explainable by sampling bias.
It's the fact that half the list doesn't write itself, that there aren't at least half a dozen names on the Gregorian Blog's list that would be on any list of "America's Fifty Greatest Intellectuals." (For that matter, would any of the Gregorian Blog's Greatest Catholic Intellectuals count as one of America's Fifty Greatest Intellectuals? My inexpert guess would put Fr. Murray as the most probable.)