Well, coming from a family where I'm the only Disney fanatic in my entire family, I never bring up the discussion of Disney vacations because I know my entire family won't enjoy it. If I did bring up for a possible family vacation, my parents would argue our family has gone enough times and that there's nothing new to see even though I've seen first hand how much the parks have changed year after year. Basically, I've learned there's no point in playing against a stacked deck or in other words, make your argument against people who will not side with you 100 times out of 100. Plus, I really wouldn't want a family vacation with them anyway. As much as I love them, there is just far too much drama that occurs on every family vacation and WDW would bring out the absolute worst for sure. I'll go on solo trips to Disney World for the rest of my life if I have to. Setting your own schedule and not having to compromise or feel being held back by others is a lot of fun.
But in all seriousness, like everyone said, Disney World is not for everyone. Some enjoy it and make trips every year if they can while others don't. You shouldn't force it on because ultimately, everyone's likes and dislikes are solely based on their personal feelings and opinions, not someone else's. Well, I'm not a parent but all I can say is: Try to emphasize that you know your husband's dislike but also say this vacation is not about him, it's all about the children and making them happy. Do not talk in a tone that says, "It's my way or the high way" because that will make it worse but rather say how you and your children would really appreciate if he would come and make it a great experience for all of you. Most importantly, tell him it's ultimately his choice. If he complies, great. But if he really doesn't want to go, don't force him to go and say you will hold no grudges or hard feelings if he says so.