Yes, some are defiant. But only those who wear jeans and such to the dining room. But as long as RCCL doesn't enforce it, people are going to ignore the rule. As long as they say "Suggested" people will do as they please. I agree, it is fun to dress up in your best for the evening. But let me assure you that after dinner I am going to change into something more comfortable and go enjoy my evening in the nightclubs or the pools. There has never been anything said about having to dress for the entire evening. For those who want to, great. But not everyone has the same idea for a vacation. That is why they have created a more casual environment for cruising these days. The windjammer being one of those.
And how would the cruiseline enforce their suggestion? They can't put the offenders in the brig. They shouldn't have to enforce it in the first place. The passengers should be mature enough to respect the cruiseline's wishes. It is this "I will do what I want to do" attitude that I do not understand. And, BTW, I believe the suggestion is worded something to the effect of "Dress for the evening is..." not "Dress for dinner is..." and they do not distinguish between proper attire for the Dining Room and the Windjammer, although I am in agreement with you that the Windjammer is more casual than the Dining Room.