Why are people inconciderate douchebags

So I am here at a starbucks trying to kill time while my mom is at a doctors appointment. I have my laptop a large coffee and wifi, live couldnt be better. Except for the 2 dumbasses sitting next to me. they are rude and immature, making fun of everyone nearby, including myself because they think I cant here them. Why are people like this? Do people really find happiness in making fun of other people? I get the cruelty, I also know there is no reason to be like that. I guess I am a dying breed that thinks people and the world could be a better place. Maybe its just california thats like this, that's the only hope I could have. In the mean time I hope they burn their tongues with their coffee.