I guess that's the case in USA. In my country, minimum wage today is 1,7 dollars per hour, about 388 dollars per month, and it has been raising in 9 dollars monthly every six months. Because of the constant inflation, lifestyle can get very expensive. Food, for instance, is just a little cheaper than in USA. To rent a small apartment costs at least 3/4 of a minimum salary, and renting just a room can cost you the same. And thousands of migrants are coming here because, supposedly, we have better job and life conditions. Peruvians, Colombians, Haitians and Dominican "join forces", and you can have 8 people living in the same apartment. In Argentina, minimum monthly wage raised from 435 to 504 dollars between January 2016 and January 2017, but inflation is so high people can barely make it to the end of the month. My mother-in-law was in Buenos Aires some weeks ago and she saw whole families with kids living in the streets and looking for food in trashcans.

Is 15 dollars an hour too much? Maybe. But I don't know if the option is ditching minimum wage laws. I can imagine that happening here and we would have people exploited like in Industrial Revolution times.