I Guess you must not be riding it as much as you think you do. I’m an infrequent rider and I’ve seen 2 altercations and multiple (10+) disturbances since January.
The funniest (or not if you’re not from SF) was a guy boarding a full bus with a 7 foot long dining table with the legs attached, arguing and threatening anyone who protested. Eventually he dropped the thing on someone’s foot and starting an altercation which delayed everyone by 15 mins.