Folks..
This is a nationwide move by the DofT to speed up security by enforcing one piece / size restrictions. Security staff are to refuse entry airside and oversize/weight or extra bags are to be checked in with the airline.
I have sympathy with those who have become used to airlines turning a blind eye (WTF?). Until now any airline that strictly enforced the policy would ultimately lose custom. Now with security enforcing the rules, there is no negative impact on any individual carrier.
As pilots we may hate the carry-on but the bean counters were too afraid to tackle it on an individual basis. FWIW I think this is the perfect solution for all - once it become common knowledge WTF!