On principle, yes. The superbowl halftime show is a good example. As an observer, sometimes its hard to tell if the artist in the halftime show is being paid by the NFL to entertain the fans or if they are paying the NFL (effectively accepting a negative wage) for the chance to promote their personal brand. If they can accept a negative wage when they want why can't I be free to negotiate the same for myself?
Yes, it is immoral. You are taking away someone’s freedom to willingly enter into a contract. Plenty of successful societies do not have a minimum wage.
Do those same societies have strong social safety nets or otherwise public, low cost means of education and healthcare. Because if so, that's a really huge difference.
