Well put. MLK preached that NON-VIOLENT civil disobedience was the only way to right the wrongs of the time. There is a mighty large difference between a sit-in and a riot.
True, although a sit-in is not necessarily entirely benign, pure and devoid of consequence. A sit-in can cause institutions and commerce to grind to a halt, inconveniencing and disenfranchising many innocent people.
Legal channels of redress typically don't shut down universities and businesses.