Without greed, no one would have invested any time or money into Bitcoins a few years ago.
Unless they believed they were doing something worthwhile. An intellectual exercise. That's not greed.
You need to appeal to people's instinctive greediness on some level to get just about any project off the ground.
So you start all your projects based on greed? That's pretty depressing. You must not do much for fun.
I don't really see greed as a problem to Bitcoins. It's a necessary kickstarter to build its infrastructure.
If BTCs were worth zero, then why should anyone care to trade them or mine them?
So yeah, greed does make the world go around.
Depressing.