This sounds horrible ! I wouldn't go to a luxury resort which is geared to families if I was travelling solo or as part of a couple. Just like OP said, he wish he would have known before he plunked down all that money. This isn't discrimination...it's called preference. It used to be that if you paid a certain amount of money, there weren't many children around but that has changed quite dramatically in this new age of parenting and wealth.
Anyhow, sorry that OP learned an expensive lesson. Now if anyone lets me know that O&O Reethi Rah has children everywhere, I will also take that one off my list.