I think the real goal is to have a range of hand positions that a bowler feels comfortable with instead of two individual releases. If you want to use pro bowlers as an example, they don't have one, two or three releases. What they have is a range of rotation angles and perhaps even tilts that allow them to achieve their desired results.
But this requires that godawful thing called practice. Some bowlers don't have the time or want to improve their physical games. Will practice make them better bowlers? Probably. But imagine the time, effort and cost in achieving those results. You can do all of that, or buy a second ball that requires only cost and no time.
I realize this is somewhat devil's advocate, but for the once-a-week bowler, it is hard to tell them they have to have multiple releases to get enjoyment out of bowling, especially on a THS that makes everything seem the same. So what they enjoy getting a new ball. That new ball can instill confidence beyond what a practice session with some new release can.
