I would agree with you other than the fact that these corporations are making record profits. They pay upper staff millions. Why would they have a need to pass anything on to the customers? The employees helped you make that profit, so share some of it with them.
The argument that people are making against you, that any increase in wages for these employees will lead to bankruptcy; closing; shareholder revolts; etc., are nonsense really. If these companies were smart, which they don't seem to be, they would pay their employees a fair wage that takes into account both keeping their costs low and ensuring their employees can actually live. If they were to do that then the unions wouldn't have a chance convincing employees to join. Unions have a potential to push their costs into a bad arena.
These companies give huge bonuses and pay increases at the top that account to hundreds of millions of dollars, so realistically, the money is there. As they are somehow able to increase pay at the top by hundreds of millions without the sky falling in on them. The problem is they can't see the forest for the trees.
Businesses like those simply cannot survive paying $15/hr, the costs of the product would go up over 50%, It already costs about $20 to feed a Family of 3 at McDonalds, business will take a drastic nose dive when the same thing costs $30+
If your "Plan A" was to work at McDonalds to support yourself for the rest of your life as non-management, you REALLY need a "Plan B"
These kinds of jobs are not meant as careers, they were meant to utilize unskilled high school level labor, thats why they have internal training for all the basic jobs. Honestly, unskilled labor simply isnt worth $15/hr
Why do you assume this is too much to pay an employee? For starters, this is occurring in NYC where the cost of living is already very high so $15/h in NYC isn't the same as $15/h in Little Plains, AR. You can also bet that the cost of a McDonalds hamburger isn't the same in those two places either.
Realistically, the employer should be sure to pay his employees a fair wage and that should not only account for how little you can get away with, but also what would allow your employees to be happy and less stressed. Everyone doesn't need to be paid $1m a year, but you should want to make sure your employees can actually live productive lives.