What you quoted is nearly directly out of the Jesus playbook. I don't have a problem with protesters playing a little dirty. Let's not pretend there are not provocateurs and other state and federal agents undermining them at every opportunity. I've caught a number of them myself. The cops play dirty too. It's a dirty game. In addition to the undercovers and troublemakers, cops use tactics meant to incite, such as we saw in Ferguson. Draw a circle and squeeze, and you'll get the trouble you seek in order to break the protest with violence.
It sounds like you're demonizing the protests not just because of tactics, but because of people. I get that there are inconsistencies in the crowd, both logical and moral. But trust me, being involved in plenty of protests when I was younger, this is absolutely unavoidable. Douchebags, impoverished socialites, airheads, hypocrites, the sexually confused, and whatever other judgmental term one can lay upon them- protests tend to be stuffed full of these people. Protests attract a lot of- those misfits who are taken over the edge of day-to-day civility by current events.
Don't make the mistake of judging a protest by the fringe attitudes you find within them. Plenty of perfectly normal, responsible, shit-together people also protest alongside the misfits. The greatest example we have of misfits making a huge positive difference was the 60's, through protest to gain civil rights for blacks and women, and to end war. You think the blacks in those protests were, on average, highly educated? Do you think the flower children had their shit together? Not on par, no. There were plenty of effective organizers back then, and plenty of people with their shit together. But from what I know from talking to my elders, the ass of the mass was made from the misfits.