In it's best possible light (aka 'snorting the pixie dust' to the jaded)...
1. While many people don't think the desert parties are worth it (I don't), you do get the desert party which is currently $70.
2. A quick serve meal: $20
That leaves $40. Would you pay $40 to guarantee your youngling a spot at Jedi Academy without having to get to DHS 45 minutes before opening?
I think many would. If I had a child, I'd gladly pay this upcharge to avoid the extra-early rope drop and mad dash to the sign-up.
The other things are gravy. Hopefully this includes not only a VIP entrance to Star Tours, but the opportunity to ride it several times in order to see the randomized scenes.
Since the desert party can only fit so many individuals, this seems like it's going to be limited to about a dozen or two each day. This will have a minimal impact on other guests.
Except that I think it would be less fun touring the park with a child locked into the tour itinerary for the entire day. What if the child decides they want to do something that's not part of the schedule?