The author mentions coupling with kubernetes due to config maps and such. That is certainly a risk, but if you use environment variables for config (which IMHO you should) then k8s makes it trivial to just map your ConfigMap to Environment Variables.

I've got a few apps running in k8s and none of them know anything about k8s. If avoiding coupling with k8s is what you want (and I agree it's the way to go) then it really isn't that bad. The hard part is not knowing what you don't know.