If you think that your "social contract" has been violated that that is because you are mistaken about the contract you entered into. This would only be immora

If you think that your "social contract" has been violated that that is because you are mistaken about the contract you entered into. This would only be immoral if you were misled or forced, and I'd argue that neither is the case here. All the contributors gave their explicit permission to use their contribution in the way Redis does. All contributors had plenty of freedom to spend their energy in projects under a license that specifically prevents what happened with Redis. It is not that they wouldn't have other options.