Greed, aka: Making more money than you could ever possibly spend in your own lifetime.
Ok, success is success. But the economy is a zero-sum game. There is a finite (however large) number of dollars in circulation. So every dollar you horde, with no intentions to spend, is a dollar that is not out and changing hands.
It is advisable to save for a rainy day (indeed encouraged). However once you get past 10 million dollars (in 2010 figures), seriously, you aren't saving for a rainy day. You are either blowing it on gold plated toilet seats, or locking it away.
And don't give me that "I'm leaving a legacy for my kids" crap. First off, half the money is going out in Estate taxes. You'd have done more for them by spending on them in their lifetime. Second, you cheat them out of the experience of earning their own way. And Third, all of that money you have locked away is kept from other people's kids who *DO* want to earn their own way.
I also don't buy the hogwash of making billions, and giving away hundreds of millions to charity. Odds are, if whatever you are doing is making those kinds of margins, you should charge less, or pay your workers more.
All in all, the intention of food is to nourish, and the intention of currency is to be spent.