The faircode model assumes that contributions from random outside people are minor and that the bulk of the work is done by the founder(s). To the founders there is little actual benefit from being an open source project, anyway. I can understand the attraction of the model in that situation.
My ideal OSS project would be receiving a steady stream of contributions from a wide variety of people without an elite sub group that considers themselves to be "the authors", which would be obviously unsuited to the faircode model. Sadly few projects achieve that and are largely the work of one person.