I think it has a second persuasive characteristic, which is simply to contrast with the claimed baseline. This second characteristic really grates on me when i

I think it has a second persuasive characteristic, which is simply to contrast with the claimed baseline. This second characteristic really grates on me when it comes in the form "I don't even know anything about X and even I know this is bad!" -- wherein people somehow leverage their lack of credibility on a subject as a source of authority. But I think it works because it makes the claim bigger by changing what it's being compared to.