Earlier quoted context omitted.
It's especially a mystery because even developments in payments from the US (eg Apple Pay) seem more widely adopted where I am (Aus) than in the US. Anyone with some insight as to why want to chip in?
In the US, the biggest adopters of Apple Pay have been big chain grocery, drug, convenience, etc. stores. For decades, there has been a (somewhat class-based) stigma about holding up the line in these kinds of places by paying with check, government benefits, coins, coupons, or anything else besides cash and credit. There's also a separate, arguably more deserved stigma about entitled people causing trouble by using…
However 'Tap and go' is so widely adopted that I haven't carried cash in months and I know people that legitimately don't know their own PIN