If you want to have family vacations for the rest of your forseeable future, you should pay for your kids to vacation with you through college, and at least the first 5 years out of college, maybe longer, or until they are capable of paying. Even then, it should be gradual.. paying for a small part until they can afford the whole.
My family cut us off when we went to college.. so 18. We never vacationed as a family after. Around the time we were in our early 30s and started having our own families, my mother decided she wanted family vacations again. But by that time, we had already established our own vacation routines and preferences. No one could agree on locations or times or prices and it never happened. My mother complains about this a lot now as she sees other families still doing vacations.
The thing is, for the people I know who family vacation, it is a routine, a habit, a tradition they are unwilling to break- even if it isnt their favorite place/vacation/etc. The first week of August or right after Christmas they always go to X location and stay in X hotel/house with the same people (and their growing families). At some point the "kids" transitioned to paying for more things. First maybe their flight, then a few dinners, etc. And eventually, they will likely treat the grandparents by paying for the house, or whatever.