Edit: it's misleading because the article actually says 65% of smartphone users download zero apps in an average month. That doesn't mean most people never download apps. Just not every month.
The better criticism of this article, is that it's already well known that most smartphone users 1) don't download many apps and 2) don't use very many apps day to day.
Why is that? It's because most apps are not useful or valuable. If they were, people would use them.
The majority of people also do not visit a hundred Web sites each day. Rather, they stick to a very small number of sites, and tend to visit them frequently. No surprise app use is similar.
That is a very significant point.
I bought my wife a Google Play voucher at Christmas, and she was so overwhelmed by the mess that is the Play Store that it took her three months to find a decent solitaire app.
Everytime she would go looking for one she had to wade through pages of junk and just gave up.
Eventually I found one recommended on a forum and even then when we searched for the exact name in the Play Store it was only in the second row of results.
App discovery is HARD, particularly for people unfamiliar with app stores. I am not surprised that they just don't bother.