Point is, they aren't throwing their $300 out in the street -- they're using it to get something they value more than the $300. To you, it may be throwing money away -- but it's their money, so what they think is important is what matters.
I am not one who'll pay for Disney tickets "no matter what." Since I am not much of a rides person, I can get my "Disney fix" just visiting the resorts and doing other on-site stuff, all of it way cheaper than a park ticket. I'm still willing to get a regular ticket, but they've already priced themselves out of my range on the annual pass. While from their perspective the per day price is lower, I wouldn't use it often enough to make my price per day low enough. While I might have gone more days with an annual pass that cost less, at that price I'd rather limit myself to the days on a regular ticket. I don't value those extra days enough to pay that price.
Point is, there probably are enough people who do value those days enough to make that price AP profitable to Disney, and more power to those purchasers. If it's worth it to them, if they're willing and able to pay that much, that's their choice. And, if there are enough people who want to buy APs at the new price, why should Disney worry about people like me? Disney and I don't have a personal relationship -- it's a (hopefully cordial) business relationship, and Disney sees me as their customer, not their bestest pal, so I don't expect them to worry about my personal preferences any more than I worry about theirs. It's not like they're coldly leaving me to starve or freeze; they just aren't offering something I want (not need) at a price I can work with.
Disney sets their prices, and I say "yes" or "no." And if someone else says "yes" when I say "no," that doesn't mean they're throwing their money away -- it means they value going to the Disney parks more than I do.