Why did pigeons get such a bad rap for being dirty and disease ridden?

Below: Pigeons are in fact very clean; they LOVE to take baths and discard of the empty eggshells after the young hatch. Ferals may have the occasional case of feather lice or mites, but that goes for EVERY animal. Even we have microscopic mites in our eyebrows and eyelashes! There is evidence that pigeons are the least of our concerns in spreading diseases to us, especially the bird flu, as they are immune to all but a few more recent strains of it. You can get Pigeon Breeder's Lung from years of exposure to their feather dust/protein, but that also goes to just about any other bird or animal. Years of being in a barn can also result in a similar condition. It is treatable, and only people who breed pigeons are in danger of Pigeon Lung. People probably got fed up with their droppings appearing in places they didn't want, and decided to hate the poor birds. The salmonella and avian flu scare in chickens apparently sparked the idea that people in cities full of feral pigeons were in danger of having it spread to them