You’re presuming that these bikers are troublemakers like the other bike gangs you saw on tv. There are lots of presumptions and few facts only analysis.
I ride both bicycles and motorcycles. I know exactly what you’re talking about — this wasn’t the case here. The bikers were making a giant pain in the arse of themselves well before the altercation broke out.
Amusingly, even the local chapter of the Hell’s Angels has called those idiots for being out of line.