The premise "many assholes are cops" doesn't need a lot of new evidence. There is more than enough existing evidence.

But what do you honestly expect riots to lead to? Concessions? Or loss of the moral high ground and even more riot gear and tear gas and escalation?

It's just handing the cops a free pass to justify arresting you. And not just arresting you, but charging you with something that could actually stick. Its hard to advocate policy when you're serving a decade in prison for arson and conspiracy.