And nowhere are you generally a jerk for not calling someone "Colonel Mustard" in a grocery store instead of "Rick". If you are in trouble for that, it's in a narrow circumstance probably involving the chain of command or some generally inapplicable honor code. The grocery store certainly wouldn't ask an insubordinate PFC to leave for being careless in addressing a superior officer.
American disregard for formalities is literally a fish-out-of-water element in Saving Mr. Banks that the British "Mrs. Travers" bristles as the American Walt Disney (always just "Walt" to his employees) keeps calling her "Pamela" because that's how he talks to everyone. And the insistence on using last names formally seems archaic to the modern American viewer, besides. The screenwriters have P.L. Travers explain why she finds that form of address too familiar instead of assuming the audience understands implicitly.
That still doesn't mean titles were banned by the U.S. Constitution, as you claim it did.
All you're showing is that the US has a lower regard for formalities than the UK (in the mid-20th century). While I don't think pointing to one film is good evidence, I agree, based on what I know from other things.
However, that doesn't show "disregard for formalities" only less regard for formalities.
A decade later, you still had Mr. Rogers talking to Mr. McFeely of Speedy Delivery and Officer Clemons, so its not like that one film was representative of a US-wide change.
In 2009 it was still the norm that undergrads call their professors by title, not by first name - http://phdcomics.com/comics/archive.php?comicid=1153 says "Undergrads must never call Professors by their first name. It's just weird."
American disregard for formalities is literally a fish-out-of-water element in Saving Mr. Banks that the British "Mrs. Travers" bristles as the American Walt Disney (always just "Walt" to his employees) keeps calling her "Pamela" because that's how he talks to everyone. And the insistence on using last names formally seems archaic to the modern American viewer, besides. The screenwriters have P.L. Travers explain why she finds that form of address too familiar instead of assuming the audience understands implicitly.