It's tempting to say that, until you realize that "trutherism" has infected the mindset of an awful lot of people, and they vote. How do you think we got an actual, honest-to-god conspiracy theorist elected as president of the United States?
When you have that many people giving honest consideration to such stupid ideas, it begins to destroy the foundations of our society.
I mean literally hurting people. I find it said when people fall for that stuff... but aside from wasting their money and time... it seems to harm no one else. Plenty of stupid out there and can't blame it all on truthers.