The failure rate for cryptocurrency experiments will be high, but I’m glad to see people trying. We’ll collectively learn from the efforts. Whatever the number of frauds doesn’t detract from the set of smart guys who are likely inventing something significant.
EDIT: I should have said "may be inventing". It's my opinion of a >50% chance that Vitalik's work will lead to something significant, for example. Some people will disagree and that's ok too.