I'm going to be travelling alone, and I see no need for dressing up sinse my wife won't be with me to enjoy the event. I'll be happy with the buffet, but I will be wearing at least a sports coat. I'm sure there are other people like me who simply see no reason for dressing formal.
I guess that depends whether you care that other people may regard you as an undignified social misfit who's totally lacking in class and propriety or not -- because that's how some passengers will perceive you if you act so arrogantly and contemptuously as you propose.
And "arrogant" and "contemptuous" are perfectly reasonable adjectives to describe anybody who books a cruise with the knowledge that it has certain expectations with regard to personal appearance and the manifest intention not to conform.