I've never understood why any group, whether I am sympathetic to their cause or not, thinks that doing something like blocking traffic would bring anyone over to their POV.
At best, you're just going to make people angry that may have otherwise been indifferent. At worst, if there is an emergency vehicle that is trying to get through and it can't because a gaggle of inconsiderate a**holes are blocking the road, lives could be at stake.
Occam's razor suggests that they're more interested in being attention whores and baiting people into a reaction. Otherwise, they wouldn't be standing in the gotdamned road.
Protest to your heart's content out of the line of traffic, ya smooth-brained yahoos.
Police here (by here, I mean the U.S.) in many places are too chicken**** to do anything about this, despite it almost assuredly being illegal to block passage on roadways in this manner. Sadly, failure to enforce laws because of perceived bad optics is not limited to poorly located protests.
To paraphrase a Chris Rock bit, "I don't think they should be moved in an illegal fashion...but I understand.'