Are there really people out there that don't enjoy their meal if the person at the next table is lacking a tux or formal dress?
No, I'm not going to let it spoil my meal at all -- but don't be surprised if I don't engage in conversation with such individuals. Of course, you can be sure that I will register complaints through appropriate channels about the staff not doing their jobs in allowing people with inappropriate attire into the dining room, the theater, or wherever else they happen to go -- and you also can be sure that I won't be the only passenger making such complaints.
I think the cruiselines are coming to the realization that not everyone who cruises is into the formality need.
They came to that realization several years ago. That's why some cruise lines have maintained traditional formal attire for those who prefer a traditional cruise experience, while other cruise lines have shifted to a more casual product. Is it unreasonable to ask those who don't want to dress up for formal evenings to book on a cruise line that offers the casual experience that they seek, and to respect the fact that other people do enjoy formal evenings?
If you don't want to don fancy clothes for dinner most nights, here are some other options.
>> Princess Cruises (Premium) -- two formal nights on cruises of seven days; the rest of the nights are casual; choice of "traditional dining" (with assigned seating and table) or "anytime dining" (open seating) on most ships
>> Oceana Cruises (Premium) -- all evenings casual; open seating in all dining rooms
>> Norwegian Cruise Line (Mainstream) -- now advertises "formal optional" as part of the "freestyle cruising" program; all dining rooms open seating
>> Radisson Seven Seas Cruises (Luxury) -- all evenings casual
I'm not sure where Royal Caribbean International (Mainsream) falls on this spectrum, but I suspect that Royal Caribbean has about two formal evenings on seven-night cruises and that the rest of the evenings are causal.
The bottom line is that you need to do your homework and make appropriate choices. If you don't want to dress up for dinner, but Celebrity Cruises clearly is NOT an appropriate choice of cruise line.