How much do you think an extra 5 years would add in terms of deterrence? It seems downright dishonest to characterize a third of his life as a joke.
Where I would put my energy into is making the risk of being prosecuted higher. If getting prosecuted is rare, the kind of people who are into cryptocurrency are going to figure that they’re likely to get away with it as long as they aren’t so blatant. White collar crime prevention needs to focus on changing that assumption.