I tried to start a tech co-op. Ours failed because of a lack of shared definitions on too many topics. What was 'work'. What was 'learning/training'. We could agree on goals, but intermediary steps towards those goals were all over the place.
Without a clear provider of vision and decision, it crumbled. This part is true of any venture, but I think becomes even more critical in a co-op since the authority is necessarily shared.