I don't understand why the Bitcoin community embraces scams like Ponzi schemes so enthusiastically. Crap, theymos had (still has?) a link to a Ponzi scheme in his sig for the longest time. It's just sad. And letting one of the least reliable forum posters run one in the main forum for "charity" is beyond embarrassing.
If you read the rules for Ponzi and still think it's a scam, you're an idiot. It's a voluntary activity.
Giving money to Nigerian princes and joining Amway is also voluntary. That doesn't make either any less of a scam. Scams that prey on people's natural stupidity and greed don't stop being scams simply because the mark isn't robbed at gunpoint.