I have not read all the threads, so if I am repeating, please accept my apology.
I don't feel that there is anything wrong with taking kids out of school for a family vacation to somewhere that can be as educational as WDW. I would guess that schools would frown if this was something that you did frequently, but for many it's a once in a lifetime trip. As kids get older it may be more difficult to take them away, but in the lower grades, I think it is a great opportunity.
Kids can learn so much at WDW, you can find something educational in many everyday things you do. Even when they think they are having fun.. they can be learning, and in the end, as much as book knowledge is necessary, life lessons are great as well!
In this day when everyone is so busy with life, it is great when a family can find time away from it all and have that quality family time that is so important!
Maybe have them keep a simple journal, or give them a camera to do photo journal. Maybe you have a budding photographer or journalist in your family!