Why?

What is it that makes some people treat rural roadsides like garbage dumps? I'm not talking about individual cans and candy wrappers - I'm talking about full garbage bags (often multiple bags) just tossed into the ditch. And it appears that "monkey see, monkey do" aggravates the problem because some roads seem to be littered for hundreds of metres. There is one stretch near me that meanders through a lovely wooded area that seems like a magnet to these idiots (perhaps because of the cover of the woods). Is this a universal problem?