Put quite simply, unskilled labor is not worth nearly as much as skilled labor. Pretending it is amounts to nothing but utopian dreaming.
Then again, the people advocating living wages do frequently live in a fantasy land. What is considered a "living wage" in my city is roughly $18/hour per person to achieve what those in support of it deem an acceptable standard of living. Having spent the last 5 years supporting myself and one other on a fixed income amounting to roughly $6/hour net (or $3/hour per person relying on that income), Now that we have a full-time income in addition to that, it comes out to ~$7.50/hour net per person in the household, which is enough for us to live, pay off student loans, and still save money every month.
I get that those on the far right are out of touch with reality, but let's not pretend the same isn't true of the far left. It takes far less to live comfortably on than anyone I've ever talked to who was in support of a "living wage." What it comes down to is people wanting to subsidize their "wants" and their lack of financial discipline by calling them "needs." Yes' the Federal minimum is a joke, but so is every instance of a "living wage" I've ever heard someone support. Both sides of the argument are dominated by a minority of loud voices from the fringes when what is needed is rational discussion by those on both sides who can differentiate between what people actually need vs. what they want in order to keep up with the Jones'.