No. Grades don't matter. At all. As long as you have a college degree, the place you went is almost extraneous. I have an IQ in the top 0.5% of the world and the only classes I've received A grades in are Computer Science, Computer Game Design, and AP Psychology.
Furthermore, a college degree isn't required to start your own company. And that's exactly what I intend to do. forget being a chump. I'd much rather be mother loving Sir Richard Branson on a private island in a hammock sending emails than some paper pusher in a cubicle.