Some people gamble by hopping on a plane to Vegas. Others speculate on real estate or stocks. Speculating on a high-yield Bitcoin investment is no different - one should only play with money that they can afford to lose. I have had a lot of fun speculating with Bitcoin, in addition to profit (despite this unresolved Pirate scheme). I'm not complaining one bit, though I find it mind boggling that so many people spend so much time and energy worrying about other people's money.
You are strangely overlooking a decisive difference. If you gamble, you are fairly well informed of the rules. The pirate Ponzi scheme was different. There is a person who set up the scheme as fraud, inventing an incredibly elaborate network of lies designed to deceive people and steal their money.
If you gamble in Las Vegas, there is nothing of the sort. If there is deception, like in playing Poker, then that is part of the rules, and everybody expects it to be that way.
Don't tell me you cannot see the difference.
Why do some people worry about other peoples' money? Perhaps there are some who want to uphold honest rules, including the rule of the law. Some people just cannot look on and be silent while watching other people being defrauded, just as some people will not look the other way when grandma cannot get across the street safely. They help as well as they can. These are the people I want to be with.