Worker coops are a good thing because unlike employer-employee-based firms they don't violate workers' inalienable rights. The justification is a principled ethical argument.
The workers' voting shares should be inalienable and attached to the functional role of working in the firm. The employer-employee contract would be abolished, so there would be no mechanism within the legal system for having a capitalist firm.
An inalienable right is one that the holder cannot give up even with consent