From what I understand, when McDonalds was cratering around when this article was written, they came up with all day breakfast. I've read several writings from franchisees complaining about the complexities of that and how it would cost them in kitchen renovations. Apparently the all day breakfast revitalized sales and McDonalds is on track for a rebound.
It kinda feels like McDonalds is being held back by their franchisees. I guess that is the downside to doing business that way.
Also, liability for the fast food workers would be with the franchisee and not the corporation. I don't know in the US but in my country, if you have more than around 50 employees or you are a public listed company, you are held to much higher labor standards than of you are a small company.