My feelings are that Zuckerberg made it "cool" to start a company again. People had such a bad taste after the dot com bust and starting a company was viewed as very risky from around 2000 to 2005. Then Zuckerberg came in with this amazing success story and now everyone wants to start a company again.
Sometimes it bothers me that people throw around the word "startup" so casually now. There's kids that are "doing a startup" but the only thing they're building is a gmail plugin or "a better to-do list that will change the world". We don't need any more of this crap. It seems like some people just want the founder title so they can broadcast to their LinkedIn network and impress people.