Agreed Hotel Tango. We have all seen folks on the same flight with Minimum. Standard and Ridiculous cabin bags. For the most part, ground agents have realised the abuse they get if they stop them and cabin crew know that to stop them will delay departure. Naturally, pax know this.
Last year, departing BOD, I had put my duty free into the hand case and had my small laptop bag outside - to make for easy access onboard. I was told (politely) that the laptop had to be inside the hand case.
So I reversed the two and carried the duty free bag on. Before I sat down, I reversed themn again. I know the rules BUT watching others with a single bag OUTSIDE the reg that is NOT tested but waved through??? That's highly irritating...