I'm a school administrator, I'm also a parent who has pulled their child out of school to go to WDW, as recently, in fact, as last week.
I recognize 100% that parents do educational things with their kids all the time. The other day I was driving my son and a friend to the swimming pool (I drive this kid a lot) and they asked me whether the "Our Lady" in "Our Lady of Sorrows" church (which we passed) was related to the "Our Lady" in the "Our Lady of Mercy" School their friend attends -- which lead to a conversation about Catholicism, and the meaning of the names of the states Mary and Virginia, and the Protestant revolution and the English Royal family . . . On the way home, we were listening to a retelling of the King Arthur story on CD, and paused the CD to talk about he different views of women in different retellings, and how they change the story according to both the culture it's being presented in and the target audeince. Both conversations were definitely educational, but I'm not going to submit a request that the school excuse my kid so we can drive to the swimming pool and talk on the way.
When I approve a request for excused absence on educational grounds, the trip has to have an educational component, AND a reason why it has to happen during the school day. My son's middle school is closed for election day, and he's going to volunteer at the polls -- a great learning experience IMO. My school is open on that day, and if one of the students asked to take the day off to volunteer I'd approve it, because it's not like they can decide to work at the polls in July when school's out. Similarly, we had a family that took their kids out for two months to travel to Uzbekistan because the father got some kind of fellowship -- since we're a charter school we could only hold their space for that long if it was "excused" which we did, because it was a once in a lifetime opportunity. I know when I was in high school I was excused to go to a major debate tournament, and I also know friends whose kids have been excused to go to Special Olympics events -- you can't choose the time for those.
But, even if they're learning a lot, the learning that happens at WDW can happen at a different time. Families go to WDW during the school year because it works for them, for their budget, or their preferences as far as weather, or whatever, not because it's a once in a lifetime opportunity. And I'm fine with that, but when they do they need to understand that the school system doesn't have the same responsibility to them. If one of my students is out for an "excused absence" of a week, because they're sick or their parent died or whatever, their teacher has a responsibility to do whatever they need to do to catch that kid up. If they're out for an unexcused absence, then the parents shoulder that responsibility. Teachers can, and do help. When my son was out last week his math teacher met with him the day before he left during study hall to review the lesson he'd miss, his reading teacher made sure the study guide for the test he'd miss was available early, and let him take it during lunch on the day he came back. They did these things out of the goodness of their hearts, and I'm grateful, but it's not a requirement.
When I went in to make the request, I simply told the school "My son will miss one day of school next week due to a family trip". They said "please put it in writing" and he was classified as "unexcused, parent approved" which basically means, he doesn't have our permission/blessing, but we know he's safe we aren't sending out the police to look for him, or calling his emergency contacts etc . . .