Why are so many street preachers such psychos?

They are extremely arrogant, and hateful. Well many of them are. They go around screaming at everyone who they disagree with, blasting a megaphone forcing people to hear their long and annoying rants about how everyone except for them is going to hell. Then if someone does something about their hate preaching, they cry out persecution. And they post this on youtube exploiting everyone who doesnt agree with them. If Im correct, I believe thats called a double standard, when its okay to brutally persecute others, but victimize themselves when someone tells them to stop. Plus the Westboro Baptist Church does the same crap.