I think one of the uncomfortable truths that people don't like to talk about in Silicon Valley is how much nepotism and old-boy-network is wrapped up in the clothing of "hiring from top schools". Social proof sounds really good until you start to think through that a lot of so called social proof actually comes from relationships built through serendipity of what school your parents could afford to send you to. It's not unusual, to steal a line from elsewhere, to be born on third base and think you hit a triple.

I see this even more with MBAs than comp sci and particularly in downturns (having been in Silicon Valley a long time now) where weaker VCs invest in MBA buddies as easy decisions in tough climates.

Credentials are great as lazy decision making tools for big co hr departments - you don't get fired for hiring the Ivy Leaguer. But for startups make sure you're hiring for what someone can do and has done, not for what paperwork they've accumulated. I've made the mistake of hiring the high flying Ivy League wunderkind straight out of college, highly recommended... it was an absolute disaster but my own fault for taking this as proxy for being good on a startup.