It's because they're anti-fossil-fuels, which, in America, means they're automatically a Liberal Plot to a certain breed of low-information voter. I've seen signs—like, full-on billboards—along the rural highway I live near saying things like "WINDMILLS KILL Families, Friendships, Wildlife, Property Values".

You've got to perversely love when the self-owns seep through. "My friends stopped talking to me because I wouldn't stop starting arguments about windmills. So now I've got this sign"