No actually I agree that it is about achieving a balance, and history HAS shown abuses can be remedied by union representation. Good, healthy companies do not actively work against their employees' interests. I am not suggesting that there is not abuse, especially in industries where there are few (if any) alternatives for workers with a specific skillset. There I can see good arguments for union representation.
You state that shift patterns are lousy for Apple retail employees. I can empathize with that as my wife works in a system where her shifts are all over the place. As with everything in life there are tradeoffs. Is working for Apple, the salary, benefits, etc worth is to deal with the shift issue? My wife has decided that yes, the tradeoff is currently worth it, but she is always on the lookout for something better. So to me, the natural consequence is high turnover. Turnover (employee satisfaction) is the a cost/benefit calculation for Apple. Are these retail employees shackled to Apple?