Why on earth did anyone give these con artists money?

If it sounds good to be true, it probably IS too good to be true.  

100% return in 100 hours means I could have given this guy $10 worth of coin, and he would be promising to pay out $163,840 in two months.  

That. Just. Doesn't. Happen.

Anyone who still had strong suspicions this was a ponzi and gave money anyway should be ashamed of themselves.  You're giving the scammer incentive to continue and letting their scheme grow, attracting more victims into the process. 

No one can force you to spend your money a certain way but for the love of god, don't waste it on losers like this.