It's a bit of an unwritten social contract that people try not to be in the way of a moving vehicle.
The middle pedal, on a manual transmission car, is the brake pedal. It is used in conjunction with the steering to either stop the car, or steer away, when confronted with an unexpected obstacle or hazard on the road ahead. This could include debris from other vehicles, road accident victims, jaywalkers, someone taken ill, or, as we have here, a spontaneous protest.
The idea is to avoid harm to the car, the occupants, and to whatever or whomever the hazard is.
It's generally accepted that deliberately driving TOWARD the hazard, with the intent of ploughing through it, is the wrong approach, regardless of whether or not the hazard should be there or not.