Of course, the owners don't want to pay their workers more, but this is not the main reasons. What they are afraid of, is that the workers reach the point where they understand that they don't need the owners at all. There's absolutely no reason, why Starbuck's can't be a workers' collective. And the owners know it, they know of their parasitic status; and the only reason why they're still seemingly necessary, is the evident disorganisation and disparity of the workers. But unions overcome exactly that. If there's such a thing as class consciousness, it is this: you don't need your masters. Thus the importance of trade unions, but also the point where they turn into something bigger.