A shift came about in the US in the 1930s with the passage of the Wagner Act (now called the National Labor Relations Act). This established elections for unionization, legal process for bargaining a union contract, etc. This made for a shift to demands and in a very specific form of posing demands. This is often taken as a major good thing for workers and it does have its advantages in some ways, but it creates problems. In the Act it said explicitly that the point was to preserve commerce, labor peace.
Quoting from this – http://clnews.org/SolidarityPapers/IWW%20Centenary%20Keynote%20Speech%20-%20Staughton%20Lynd.htm

it’s a piece by Staughton Lynd. He talks about Martin Glaberman, who “argues that in a workplace where there is a union and a collective bargaining contract, and the contract (as it almost always does) contains a no-strike clause, the shop steward becomes a cop for the boss. The worker is forbidden to help his buddy in time of need. An injury to one is no longer an injury to all. As I say these words of Marty Glaberman’s, almost forty years later, in my imagination he and the other departed comrades form up around me. We cannot see them but we can hear their words. John Sargent: “Without a contract we secured for ourselves agreement on working conditions and wages that we do not have today. . . . [A]s a result of the enthusiasm of the people in the mill you had a series of strikes, wildcats, shut-downs, slow-downs, anything working people could think of to secure for themselves what they decided they had to have.” Ed Mann: “I think we’ve got too much contract. You hate to be the guy who talks about the good old days, but I think the IWW had a darn good idea when they said: ‘Well, we’ll settle these things as they arise’.” Stan Weir: “[T]he new CIO leaders fought all attempts to build new industrial unions on a horizontal rather than the old vertical model.””

Sometimes making demands in a certain way – in the way which the state tries to channel us toward – limits our abilities to problematize, and don’t increase our compositional power. That’s part of what can happen if one follows the mainstream model for workplace organizing – the institutional aspects, the mode of posing demands, tends to gradually undermine the bases on which the power to make those demands rested. In the process it also statifies that power. Put differently, the power to produce compositional effects, movements in social relations and subjects, declines more quickly and is more immediately limited by certain forms of posing demands – a group can still have the power to win external gains in the early stages of a local decline, but the results of those struggles are more limited to the external rather than the transformative.