Concerns about quality
One of the issues here is reaching consensus in a timely way. If you have a group of collaborators with widely differeing views it might take a long time to get a consensus on any one point and if new ideas and views are continuously being added to a resource, the realisation of a new product might take a long time.
Collaborative authoring is a good idea as it enables more than one person to check the accuracy, and validity of a resource