Only because they are such EASY targets!
We were discussing this very subject this morning, whether the uniform (big gut, bandana, jeans riding 1/2 inch above the hip bones, big boots, leather vest, bald patch and straggly pony-tail) is a requirement for owning a Harley, 'cause let's face it the 'look' really is a uniform. If you were to walk down the street in this get-up would some grizzled Harley rider approach you and say "You need to buy a Harley mate, you already look the part!"???