This subject was discussed on the Restaurant board a few months ago (couldn't find the post, though). Basically, the response was the same, with some thinking it's a great idea, some not.
I'm a parent to an 8yo and 3yo. We dine out
a lot, and we dine in casual to moderate restaurants with our kids, upscale and pricey without them. My kids are pretty well behaved and have never screamed at the table, ran around or thrown food. Wait, I take that back. I think maybe two or three times over the last 8 years, one of my kids has done the "I don't like this" and thrown the half a sandwich back down onto her plate. If someone else is bothered by this, I'd suggest that person turn his attention back to his own tablemates, as it would not have been noticable by anyone not watching my table, and why on earth would anyone be doing that?
Like others, I have never witnessed a child actually "throw" food or otherwise do anything so disruptive that it could possibly ruin my dining experience. I'm not saying it never happens, and for those who have had special dinners ruined by unruly kids (or adults, or rude waitstaff...), I'm sorry that it happened to you. What I'm saying is it's the exception, rather than the rule, and I just don't understand how certain people seem to have so many meals ruined by other people's kids.
But with that said, the point is that it's not up to me to understand what other people are or are not bothered by. I know that I'm pretty good at tuning out the sights/sounds I don't want to see or hear, others may not be able to do so as easily. If people want an adults-only restaurant at WDW, IMO they should have one. I personally probably wouldn't dine there, but again, that doesn't mean others shouldn't have the option if they want it. With so many restaurants at WDW, it's no skin off my nose if a few of them won't let me bring my kids in with me.
But it's purely business as far as WDW is concerned. If they thought it'd be profitable, they'd probably do it. For those of you who really want it, write to WDW and let them know. I hope they open one up for you.