"you just need to create something very cool that you and other people find useful."

No. You need to convince investors that whatever you have is "cool" and "useful", even if it burns money.

Derby is cool. Express is cool. Knockout is cool. There are so many cool, free, open-source libraries. It has become crystal clear that getting investment is about being on the inside, having a hip website, and valley celebrities saying good things about you.