Marcus, what a great post! At one point in my life I also decided that I will not deal with negative people and their hurtful ways any more. It took some time, but I learned to feel rather sorry for them and to forgive them for their inability to accept others as they are and be happy.
Just as the writer in the article points out, once you engage in the same type of behavior it is easy to become just another garbage truck!
A friend of mine once said when s.th negative is thrown her way, she puts on a smile and goes through the act of brushing it off her arms saying: "Off with you"!
Sitting in traffic once, I actually saw someone do that in a car next to me. Another person had turned suddenly in front of her and rather than blaring her horn, she just went through these motions. I had a real good chuckle and thought good for you! There was no mistaking, she was not going to get affected in a negative way!