Despite the Silicon Valley's somewhat undeserved reputation for breaking with tradition, at least having attended a top university is so close to being a requirement in SV that it might as well be. Try getting a job at a top-flight SV company without a degree, or even with a degree that wasn't from an Ivy League school...you'll find it nearly impossible. There are exceptions to every rule, but if you don't plan to work for yourself, you'd better either have a decade or more of solid, demonstrable experience that yielded exceptional results, or have a degree from a top school.