Collective bargaining isn't the problem. It is the strike that is the problem. When GM workers go on strike, I can still buy a car from 20 other car companies, as well as ride a bus, bike, skateboard, or walk. When public union workers go on strike, they have a much larger position of power because they have monopoly control over a societal good. When teachers go on strike, the children who rely on public education are the ones that suffer...not the teacher's employers.