My understanding of colleges is that they tend to accept pretty much anyone if they aren't coming straight from high-school. The idea is that people who have lived in the Real World™ who choose to go to college understand why an education is important and will naturally work hard for their degree (because they see it as one of their last chances to escape from whatever situation lead to them applying), whereas high-schoolers only want to go because they've been told they have to in order to be successful.

Obviously this isn't true for true Ivy-league schools, but it does tend apply even to larger state schools, such as the ones in this article.