By "everywhere" I meant "in at least one neighborhood in every major U.S. metro." I did not say (or mean to say) that it's possible anywhere in every U.S. metro, just that it's possible somewhere in every U.S. metro.

(I mentioned my experiences with high Walk Scores in St. Louis to imply that they are anomalous in the St. Louis metro, but that dense, walkable neighborhoods exist even in such car-centric MSAs.)