Their pictures were used in a commercial, for-profit setting without consent.

Being "used in a commercial, for-profit setting" is not a thing.

Their images were not being sold, nor were they being used to promote the concert. Plus, nearly everyone who goes to a concert these days agrees that their image will be captured and possibly used in future promotional material.

That's what caused the "outrage" (perhaps more "discussion", "introspection", ...). And without that, there is no art.