Both valid comments, there are a few quick answers to make the severity of these problems perhaps less worrisome:
1) the average investment in a successful crowdfunding campaign is only $96. So, the real risk vis a vis the founder's self-proclaimed valuation is not only mitigated by this average, but there are also caps on how much a retail investor can invest annually in crowdfunding. For instance, anyone earning under $107,000 annually, can only commit $2200 or so. 5% of their annual income. I'd say there are far more dangerous "investments" people make with far more predictably bad outcomes (hamburgers?).
2) as to how to know if other, potentially better, candidates for your money are making similar solutions available to investors, that's always hard to say, but I'd say you might reconcile "Caveat Emptor" dictates responsibility in both of these questions: "the principle that the buyer alone is responsible for checking the quality and suitability of goods before a purchase is made."
So, do your homework. I mean, you' wouldn't buy a house sight-unseen without looking over the neighborhood, checking out the schools, etc.
Great questions. Keep em comin'