Soft-spoken Zappos CEO Tony Hsieh had some surprisingly harsh criticism for the TC50 companies he saw today: Why aren't you trying to change the world? I asked him more about that in our backstage sidestage interview during the TC50 cocktail party. "To be fair, is selling shoes changing the world?" I asked. Watch the clip after the jump to hear his answer.I pressed Hsieh on details about his relationship with Jeff Bezos and Amazon. He can't really comment because the US Justice Department hasn't yet ruled on the deal, but he did admit "I've always thought Jeff was a lovely man." So that's how it works in that soon-to-be corporate family.The most interesting admission may be his advice for start-ups: Do you really need venture capital?TechCrunch50 Conference 2009: September 14-15, 2009, San Francisco