I've seen a lot of public prank videos, and even the lighthearted ones where it's a scare prank or something makes me nervous. In some of those scare pranks, people spill their drinks on themselves, or take a fall. What if they seriously got injured? Yeah, it's fun and games, but pranking strangers is iffy at best.
In this case though, it really appears as though the guy's pranks were much less lighthearted in nature and more aggressive, taunting or just plain annoying without being funny. Strangers, for the most part, don't want to be targeted by that. They don't want to be the source of your clicks.
I don't know the exact details of what led to this guy getting shot, but he's a rather large dude, and if he was being aggressive towards the shooter, I can totally see why things went down the way they did.