Did anyone say Disney should become a sandals resort? No. No one said those words at all. No one wants to change Disney from a family vacation destination. I think restricting some restaurants to adults only is a GREAT IDEA. I know most people would throw out the line "then don't go to a vacation destination aimed at families" but sorry, that won't work on this one. Walt Disney World is NOT JUST for children. It's for adults as well. There are many many restaurants for families there. So having some adult only dining establishments wouldn't be such a bad thing.
The following is just a lighthearted discussion and my views - sometimes hard to tell on these forums.
Sandals resorts are not just for adults, but they are adult orientated. Adults can have fun at Disney, but it is family orientated which means you are going to find kids everywhere and limited adult only entertainment. Now we both know adults can have fun at WDW, but if I poll 100 adults about fun vacation spots for adults, we'd be the only two who would say WDW.
I'm guessing Las Vegas, New Orleans, and Napa Valley would top the list. Kids can have fun at these places also, but they are geared towards adults - remember when Vegas tried it's family friendly ad campaign and now they're back to "what happens in Vegas stays in Vegas?"
I'm not opposed to adult nightlife in Disney. Hey, I look for it. A few years back, my brother and I convinced the resort bartender to let us drinks some beers and such as he closed down and did some cleaning. His usual last call was 11:30. He said the resort bars close before midnight so mom won't yell at Disney for ruining the family vacation by letting dad stay out all night drinking. We left the bar a little after 1 am and I did get that look the next morning as I was moving slow to our early ADR.
But I believe part of the Disney magic is in their restaurants. They allow average theme park goers to experience international cuisine or upscale food (a foodie would probably debate this) in a very relaxed atmosphere (V&A is the exception, but they don't allow DDP or now TiW). Hence the typical dress code and the fact that most of the year anymore it's included in a package. Now would I take my kids out to a upscale local restaurant at 8pm on a Friday night, no. But, I would at Disney, because it's Disney.
If Disney thought they could make more money by having more adult only restaurants, I'm sure they would do it. However, WDW can't be everything to everyone, Vegas tried and failed. WDW resort is a family orientated destination, thus very limited adult only venues.