I cannot say I'm very impressed with the article. I could pick out a number of millenials who are doing better than their parents at the same age. But I wouldn't use that to argue that everything is okay.
One thing that has stuck out at me has been the ways in which people have money drained from them. I think there is a huge student loan problem where young people were "sold" a crappy education. But setting that aside for the moment there is a huge difference in lifestyle that I see in people; going out to eat more, paying for basic entertainment, communication charges, credit, and transportation.
Something that seems to be missed on people is that debt is very corrosive to your future wealth. People who carry a balance on a credit card, month after month, may feel like its "okay" because they always have enough to at least pay the minimum but it isn't. When they don't take the time to each bag lunches, breakfast and dinner at home they are sending more of their money out into the world and out of their future. When the world tells them every car has to have backup cameras it means they are going to have bigger car payments. Coffee habits, in app purchases, cable TV instead of free over the air TV.
Some people budget badly, some don't. But before you slam an entire "generation" I think it makes sense to look a bit deeper at the forces at play.