If you think about it for a moment, it's the same principle that causes people to become compulsive gamblers. They are rewarded JUST ENOUGH, by chance, to keep plugging coins into the one-armed bandit. Very, very few people ever really recoup their losses, but they hang in there, hoping for the big payoff.
So this isn't JUST about THEM, but also about US. We have to open our eyes and stop throwing figurative (or literal) good money after bad.