I’m not sure that the evidence provided supports New Atheism’s ‘failure’. Yes, the majority of Nones are not self-identified atheists, avidly consuming atheists websites (even assuming of course that the popular websites from the author’s day are still the main hubs of atheism). But then again, according to Barna, only a small proportion of Christians are “Resilient Disciples”, proactively participating in Christianity. Unbelief has its “Nothing in Particulars”, just as Christianity has its more passive “Nomads” and “Habitual Churchgoers”.
It could be argued that New Atheism succeeded in creating space in the public sphere for unbelief, and can claim some credit for the growth of the larger group of passive unbelievers, as well as the smaller group of active ones. Also, nothing stays “new” forever, and to the extent that New Atheism has succeeded, it is becoming simply a part of the contemporary viewpoint of Atheism, and becoming less and less distinguishable over time.
Addendum: I’d also like to add these Google Trends on “christian apologetics”, “biblical inerrancy” and “christianity” as comparators to the article’s atheism-related trends. Should we likewise be asserting that Christianity has failed?