Nothing new or surprising.  This facet of Judaism has been around as long as there have been Jews.  “The fool says in his heart, ‘There is no God’” (Ps. 14) seems directed as much at the internal corruption of the Covenant people as at the surrounding nations. 

This is the kind of resume padding we can expect to keep up the “growth of atheism” narrative.  “Behold!  We’ve discovered many nominally religious people who are actually atheists!”  Haven’t they ever sat in on church board meetings or conventions?

I think this is why Jesus was known to have said, “God can raise up these stones to be children of Abraham.”

Agree. You can be a “cultural” anything. That’s nothing new. I think it’s especially comfortable to be a cultural Jew because of the very real and poignant shared history and existence of Israel, which can make Jewishness a nationality as well as an ethnicity, religion, and culture.