Most of those pedestrians are crossing against a red light. There's only a couple of instances where he's a bit out of line in my opinion, while almost all instances the pedestrians are either clueless, obnoxious or both. It's his way of reminding them too be more alert and to show that pedestrians can indeed be a danger to themselves and others.
But sure..., having such a loud obnoxious bike in the first place is a bit twattish I grant you...