People aren't clearly separatable into "owners of capital" vs "workers", you're right, but they don't have to be. You just need to recognize that the role that they play at any given moment can be so categorized. And sometimes they play many roles at once - for example, a company owner who is also its CEO is both a capitalist and a worker, and fair wages that he receives as the latter (fair here meaning that an equally capable manager hired from the side would ask for this much on average) is not a problem.