Maybe it was the mix of nationalities onboard?
I have found the Brits to be pretty formal - like on Cunard.
But I have also been on MSC cruises and the French and Germans were the most casual cruisers I ahve ever seen. It was honestly as if they didn't even know what formal means on a cruise. They hadn't a clue.
I am the editor, but I also speculate, ask questions and play devil's advocate. I reserve the right to change my mind.