A lot of tourists jump from the bridge, but most of them get hurt badly. Just two weeks ago an American jumped and broke his spine. Every year at least one dies because of that.
It takes a lot of courage to jump, and even more skill to jump correctly (not just throw yourself from the bridge).
I have jumped from higher quarry walls in Southern Indiana near Indiana, University. Obviously, diving off the bridge is extremely dangerous, and many tourists would be drunk, that is not going to help. But, generally overall it seems rather straight forward, but it is a lot more dangerous than bungee jumping. I am not going to rate this is highly dangerous, but generally highly stupid for a tourist to do, that does not speak Croatian or Herzegovina language.