The title is overselling it. One paper was wrong. Plenty of other economists didn't see anything wrong with raising the minimum wage to $15/hour. There are figures that are too high, but $15 is not too high for Seattle.
That is key in my view. We should do away with a federally mandated uniform minimum wage all together and instead mandate that states pay a minimum wage that makes sense for their state. Get all the smart economists in a room and figure out what formula makes sense whether its based on the state level GDP (or even county), cost of living in that area, economic opportunity, etc.
While $15 isn't too high for Seattle restaurant workers, it is much too high for a rural North Carolina town with population 15,000 where there are a few restaurants in town and the average plate cost is 9 bucks and the center of the town is the Walmart shopping center.