Sergey Brin went to the University of Maryland. Larry Page went to Michigan. Marc Andreessen and Max Levchin went to the University of Illinois.
This not to say some schools aren't better than others, but when people do great things it's usually because of who they are rather than where they went to college.
Well, I'm not fully agree on the examples with Sergey and Max. Sergey's father is a very qualified ex-soviet mathematician, he gave very good basics to Sergey. Max moved to US when he was 16. He's got grounds from the soviet education system, which was very different comparing to US. So, their college choice (theoretically) could not change their fate. ;)
But in overall you're right. Don't treat college as your pass to success, however it could be your backup, just in case if you're not that smart as you think. ;)
This not to say some schools aren't better than others, but when people do great things it's usually because of who they are rather than where they went to college.