Personally, I am quite pleased that Disney made this choice. I didn't purchase my AP with the expectation that I would be going to the park more than once or twice a year. I did buy it with the expectation that it might give me access to special events like this one. I approve of the concept of "paying to play." And, I hope Disney stages more events that are available to AP's for a premium.
As to the charity angle, what was underhanded about it? The description of the offer does not say that part of the proceeds from your ticket purchase will go to the two charities. I certainly didn't purchase the tickets with that assumption.