A few business realities (no this is not the "It's a business deal with it" post) that no one has brought up yet...
Disney reports "Average Guest Spend". For Disney, the perfect formula is fewer guests spending the same amount of money. So yes, raise the prices of drinks, even if it cuts down attendance (since attendance = operating expenses).
So if fewer people come into the parks, then they can cut back staffing, etc. but maintain their income by raising in-park prices to keep the Average Guest Spend growing. If you have been following the quarterly stock announcements, this is exactly what is happening. Of course there is a tipping point, and that point is open to debate, however they are not there yet.
On a side note, we disregard the details, but honestly, those of you who are not AP holders, locals, etc... haven't considered NOT going and waiting until Star Wars Land opens, or the 50th. It only takes a few people to hold out for the new stuff to pull down park attendance. It doesn't mean anything about the product. These pre-new stuff dips always happen.. the bigger the new thing, the bigger the dip.
Finally... don't forget about the lockers. I bring in lots of drinks and store most of them in a locker. Stop back as needed to reload.