The article is filled with nonsensical points. I tried to make a list, but didn't want to post a wall of text.

"even if these gains merely reflected the fact that old people are getting richer, rather than young people, it wouldn't make much of a difference to my general argument, as millennials will eventually get older, and thus benefit from these gains just as old people do now."

Let me rephrase that: even if I'm wrong and millennials are worse off, I'm sure they'll do better later.

Further down he answers the question about whether it's harder for millennials to buy a home with the national home ownership rate... a stat that isn't broken down by age group.

I read this entire article and I regret it.