One hypothesis: what if (genuine) civet coffee is so good, because the civets' nose smells out the very best coffee cherries, and only eats the best? Therefore, if it's crapped out the arse of a civet, it was a very good bean.

Given that many animals have a superior sense of smell to humans, this hypothesis seems reasonable - civets could smell out the best coffee, and given the choice, who wouldn't want to eat the best?

If this is the case, then the whole mass-production/feeding-civits-in-cages is absolutely pointless, because it does away with the civets' selection process. Which might explain why some people describe their purchase as watery and bland.