This is ludicrous. If my daughter wanted to meet Elsa (and she does) and Elsa was MIA, I would suck it up, explain the situation to my daughter and move on. Things happen. I certainly would not feel entitled to compensation.
Nor do I want my child going through life expecting compensation for every little disappointment---that's just part of life. I certainly would not allow something this trivial to ruin my day.
I don't think anyone is asking for monetary compensation. But, I think it's perfectly reasonable to ask for a FP for Elsa for a different day. After all, if it was regular FP I would just show up another day to grab one. But, FP+ advance booking makes that impossible so Disney opened this can of worms they need to have a recovery in place.

After all, if I am required to figure out what my whole family is going to feel like eating 180 days in advance and now how to book our rides around that 60 days in advance as well, then I expect Disney to hold up some part of this. I wouldn't go crazy I would just explain calmly how they can make it right. They created the problem with FP+ and ADR's with penalty fees.
As far as CRT, well if that happened I would expect to be able to come back another day of our trip to get the picture with Cinderella. Now, I would have been happy had they substituted a different princess like Aurora and put the FG in the rotation upstairs. But for our picture package and the price for our family of 7 I want a princess.

I don't think it would hurt to let some families get in line for the picture with marked receipt from previous day as she's downstairs and not in the restaurant.
ETA: The reality is they created this with all their advance planning hype. The supposed trade off for less FP'es was the being able to lock in your favorites in advance. ( I don't want to get into the argument about the 4th FP but bigger families like ours can't count on much being available. So the trade off for 3 is I can lock in my DD's A & E FP then that's what I expect.

) And as a PP mentioned the hassle of staying up until midnight and going through several issues as their website still doesn't work correctly all the time means that people have an expectation. And yes on a ride breakdown we have been issued a FP to come back later so I would expect that for A & E. Refurb is not the same as you never book a FP + for that anyways as it's not available.
Disney wants the benefits of locking people in then they need to deal with the consequences of that brilliant decision.
