You're assuming that the recruiting situation is the same at most of those universities. It's not. Most kids who commit to Florida, Miami, and Texas A&M commit locally or a short drive away. That means that even when there is a disappointing season, there are enough fans around to help them feel positively about the team and they're a short drive from the campus. ND doesn't work this way. We get one shot to get a kid on campus and let him know what we're about. Often we send that kid right back into the arms of the local fan base. It's really hard to justify to your friends in high school (who all root for the local team) why you're going to go so far away from home (and parents), leaving the local favorite, and (oftentimes) not following in the footsteps of the old high school's heros. It's exponentially more difficult for a kid to do that when the team that they are doing this for is telling you they're BCS bound, and lose to USF in the first week.
Florida can have a disappointing season, and the Florida kids will still go to Florida. Texas is the same way as is USC. But it has been shown that ND rolls in wins, and then recruits, in that order.