I've never understood the idea that having somebody at the next table who isn't dressed as nice as you somehow detracts from your "experience". If they are well-groomed, clean, and well-behaved, and somehow that means you can't have a romantic meal with your spouse, well, all I can say is that's a shame.
Beyond that, I can't buy into the discriminatory thing either, though I agree in concept that if there is any kind of material change going on here, its a bad idea.
500 options? Ok, so we're counting churro carts and I really don't think a churro is a viable alternative to a sit-down dinner. As good as the Nestle Tollhouse Chocolate Chip Cookie Ice Cream Sandwiches are, even I can't approve of having that for dinner.
So let's be realistic and just included sit-down and counter service, and that's why the 2% isn't a practical number to use. And if we want to really be accurate, we're only talking about sit-down dining options, and now this really is becoming a significant percentage.
Again, this isn't likely to affect me personally in anyway, because I've never gone to any of the restaurants on that list, or any other comparable place on property, in less than walking shorts, non-flip flop sandals, and a collared shirt (usually an Aloha shirt, btw, frequently quite loud). So this isn't coming from any personal aversion to meeting that kind of dress code.
Its just that WDW is not the place for it. Its a bad, and yes, exclusionary move to expand it. The people who want to dress up are going and dressing up anyway. Those who might want to wear flip flops or a clean t-shirt will now likely not go, and also feel like this isn't quite the type of resort they thought it was.
And again, on the subject of t-shirts and tank tops, I think some need to take a quick trip to the ladies' department at Macy's, Nordstrom, or another upscale department store and see what falls into this category.
Kids need to learn the social graces that will be required of them as adults and knowing how to dress properly for a special occassions is one of those life lessons.
Having dinner at the hotel restaurant in WDW isn't all that special an occasion. We're talking about families that are on vacation and probably spent most of their day in a theme park in hot and humid conditions. For most, this isn't the type of "special occasion" to which you are referring. Besides, having a dress code like the one listed isn't going to accomplish anything in this area anyway. If the parents aren't teaching their kids the proper way to behave in restaurants, its folly to think this will actually change that. That rampaging 3-year old will now just be doing it in their sneakers instead of flip flops.
You aren't going to significantly change the culture at WDW or its restaurants just by posting this rather minimal, but still more restrictive dress code. I'm sure Disney knows that. If they don't, then they really are clueless.