In the grand scheme of things, I doubt the education differential between Americans and the Swiss is enough to explain why direct democracy works in one place and not the other.
Maybe californians don't have a sense of ownership towards their state as much as swiss people have.
I don't think you can really compare between systems drawn differently. The nine-county Bay Area is as populous as Switzerland and you can bet that the Bay Area by itself would pass wildly different referenda than does the state of California as a whole. Consider what would happen if you threw together Switzerland with Austria, Bosnia, Serbia, Croatia, and Slovenia. That would be about the same size as California and I'm sure the plebiscites would be hilarious.