Silicon Valley is an idea that represents an industry, analogous to Hollywood, Wall Street, MSM, academia.
Sometimes these concepts are geographic, sometimes the geography is totally symbolic. For example, there are people who are definitely part of Silicon Valley who live and work in New York. And there are people in New York also who are part of Hollywood.
Saying Silicon Valley thinks college is a waste is like saying Hollywood is fighting piracy. Or Wall Street supported Romney in 2012. Believe it or not I am part of Silicon Valley, and I sure don't agree with the idea that college is irrelevant, so it's not an absolute or unanimous thing.
We say things like this all the time, often to explain what we don't agree with. It doesn't make sense to spend a few paragraphs stating exactly what all the people in tech think in all its variants. Even if Paul Graham hasn't heard that Silicon Valley thinks college is a waste, the students have. I went to his Startup School and talked with a few of them. I worked at NYU for a couple of years, and saw all the energy drawing students out of school and into startups. That pull totally came from tech. The students hear it even if Peter Thiel is saying something subtly different.
So that's what I wanted to respond to. And I think I wrote a pretty good essay. It's certainly resonated with a few people (except in PG's backyard). I believe there's something there.