There are reasons this could work and reasons that it probably will not. It could work by providing players with a professional environment, NFL level playbook and terminology, and NFL level preparation. If you want to know where players fail is that they don't know how to work, struggle to compete physically, and get lost in the complexity of the pro game. If a league can address these issues, it could be a success. If not, it never will. You need to have a success story if you want to keep your doors open and be taken seriously.
All that said, the NFL is about what you are comfortable with and I still find it tough to believe NFL teams would cut a player they drafted in the past yera or two for an equally unproven guy with, more than likely, less athletic talent.