We've created them.
They have as much right to speak their mind and spew as much vitriol as I spew Shakespeare...the same way we've made me into the seeming embodiment of the long-winded pseudo-intellectual Ivory Tower elitist, we've created these trolls, too...you pay them heed, and you lend credence to their creed. Respond, mute them, ignore them...but they have their right to speak, too...