Many of them are more attitudinal than infrastructural, but they are important to start-ups nonetheless. Tech startup companies need low-rent startup space. So start-ups tend to start lean and mean and move up as they grow. That means more short-term leases, which means successful startups end up moving to the next bigger facilities a lot. And that means that the office furniture and cubicle rental business is thriving.
Venture capital is of course critical to the success of startups.
But the Silicon Valley VC's are hardly typical. The least important thing they do is loan startups money. The most important things they do involve analyzing startup plans, and rejecting poorly thought-out ones early on. These VC's tend to be much more willing to take risks, albeit calculated risks. They figure they'll hear 1000 business plans out of which they will seriously study 100.