Deflation doesn't only mean that prices go down. It also means that wages go down, or unemployment goes up. There hasn't been a healthy economic period in a modern nation which was undergoing deflation. Japan had it during their lost decade, and we had it during the great depression at extraordinary rates of 10%+ a year. The logic that "prices go down, therefore it's good FOR TEH PEOPLEZ" that these people embrace just paints them as the economic novices that the are. They think they're saying something profound when they're just cranks reinventing old errors.