We have all played games where we ask ourselves, "How could this be considered finished?" Commands are delayed, backgrounds are noticeably recycled, animation is jerky, the difficulty goes off the map after the first stage, and the voice acting has all the quality of an elementary school Christmas pageant.
Typically, the responsibility of a game's production lies with the producer. The producer oversees virtually all elements of production, from making sure the development team is sufficiently coddled—or threatened—to scrutinizing components of the game. Make no mistake, it's a tough job, and it's a lot tougher to realize a great game if you're a full-time employee of the development company or distributor.
Enter the independent, freelance producer. The industry needs to deploy, or employ, producers with no vested interest in the development or publishing company other than a paycheck at the end of the gig. The only thing the independent producer (IP) is concerned with is putting his or her name on a quality piece of work. This system works in movies, TV, and the music industry. It takes a very talented person to fill this role, and, as such, they can command a good price.
Beta testers are valuable, but they can only hope to fine-tune a game and not command a major overhaul. The IP would ensure that a major overhaul is not even an issue.
An IP is not restrained, or enslaved, by the same factors that a company man is. The company man must balance his reputation and his job. So he's going to make compromises to appease his management. He's aware, and afraid, of budgets, deadlines, legalities, and the hiding of bodies of uncooperative team members.