Unions used to blanket-strike all member shops, not just the problem ones. That's what people forget wrt the 1930s cartoonists' strike (it actually wasn't Walt or his company that was the problem, it was WB and, I think, AAP, but they ALL had to walk because of the fucking union). That had to stop for 2 reasons - unions diversifying too much and the CAW completely breaking off from the UAW over Canadians being forced to walk over issues that didn't affect them at all, while Americans never voted to strike when Canadians were getting shafted.