It is too bad that the scam/ponzi collapsed ~2 years ago and the money that was stolen has long been spent, making it unlikely that investors will ever recover. Plus the fact that since his ponzi collapsed many others have followed in his footsteps who will likely not be prosecuted because their scam was not large enough to get the attention of law enforcement
This case is a criminal one, so it's about retribution more than anything else. A lot more people are deterred by the prospect of a jail term than by a civil judgement or a fine. No, it doesn't make victims whole in any way but if he were to receive a substantial sentence then it sets a precedent for the future and sends the message that fraud using Bitcoin is still fraud.
It wouldn't deter every would-be fraudster, of course, but knowing that there's already someone serving a long jail sentence for Bitcoin fraud will deter some people from a similar path. Right now, we can't point to much in the way of meaningful consequences which have been suffered by those who've perpetrated Bitcoin frauds - the sooner that changes, the better.
