I think there are two Silicon Valleys.

The biggest companies like Google, HP, Intel and Apple are able to work on products so complex there is a ten year time horizon, and occasionally we get a company like Tesla, but the overwhelming number of the angel investor startups are about marketing first and technology second, so the "non-technical cofounders" are looking desperately for technical cofounders.

Amazingly this even describes some of the unicorns. Uber was ahead of the curve by a year or two with a mobile app, but Uber is big because it has money for expansion and the war chest to fight city hall.