Several people in this thread are forgetting that Disney is a business, first of all. They keep raising prices and profits keep going up. It would be irresponsible of them NOT to keep raising them. Yeah, it sucks for me and you and lots of other people, but it's working from their perspective, so they keep doing it. Again, they have to.
I doubt very seriously that there's going to be a magical tipping point where, all of a sudden, attendance drops by 25% or anything crazy like that. There will be a point where it completely levels off or even decreases slightly and who's to say that's not what they're looking for? If they lose attendance, who are they going to lose? I know we all think we're valuable, but if you're scraping together money to get to go, you're not as important to Disney as the people who don't even look at what they're getting, don't compare, because they have money to burn. Give me the DDP Platinum Diamond Edition with optional rally funpack and the 10 day, no expiration, waterparks deluxe, with cheese, I just want the best.
As others have mentioned, it's all about profit per guest. Those are the people they want. Not me. Vote with your wallets and your backpacks full of sandwiches and bottles of water. They don't particularly want you there, in the first place.
They want those people who will buy high-dollar tickets and then only actually come to the park a few hours a day and skip some days, eat at expensive restaurants, do lots of shopping, go the the spas, play golf, etc. What's the result of that on the parks? Less people = less staffing = less food = you get the picture. They could easily show a decrease in guests who make up the bottom few percentage points of spend (which likely means lowest percentage of income), only to make more revenue with less expenses.
Now, you've also created a better guest experience for the spenders, because you've thinned out the crowds, somewhat, and specifically removed the people they'd prefer not to be surrounded by, in the first place. Perhaps their spend now even rises, because they're having more fun, getting to do more. Isn't that exactly what they're about to do with FastPass+?
Disney may very well be intentionally trying to price out the lower tier.