capital is the automatic subject; the specific personification is of marginal significance. co-op capitalism merely turns workers into managers of their own exploitation.
exploitation does not hinge on abuses of power, how much workers are paid, or even distinct personification. in the first place technical usage, exploitation is simply surplus-value.
in the broader sense, exploitation hinges on whether one’s abilities are used for the benefit of another to one’s own detriment, where the nature of the subjects in the relation are under-determined.
marx speaks of the exploitation of machinery, for example. the same logic applies for personified capital, where the exploiter cannot be simply identified as a human individual.