For me, the question isn't whether or not WDW is too expensive, it's whether its too expensive to stay onsite for more than a few days.
For now, it's still worth it to me to be able to stay onsite. I've been to Florida so many times that I'm not really interested in a vacation there that doesn't involve Disney. I love being in the Disney Bubble. I love not needing to use a car the entire time I'm there (it makes it really easy when traveling, as I do, with a party of extended family members). I love the feeling that I get staying onsite, and a huge part of my vacation is relaxing at the resorts. I don't mind the planning that goes into a Disney trip, and we've been so many times that we're ok winging it with ADRs sometimes. These trips are not inexpensive, especially since we stay in deluxe or moderate resorts (with the odd few nights at a value at the beginning of a trip). But for many in my family, WDW is our happy place, and we find it worth it.
The only thing that would push me away would be if the parks were crazy crowded all the time. So far, I'm lucky that my schedule is flexible enough that I can 'chase' the moving times when crowds are low (used to be October, then early December, lately we've gone in August). I've gotten very lucky with discounted rooms because of the times of year we tend to go. I also don't do big Disney vacations with my DH and kids every year. My DH actually doesn't like Disney very much and has more limited vacation days than I do. So I bring my kids to WDW every three or so years or so for our annual 'big trip' that lasts a week or longer, and on other years, our 'big trip' is to a place where DH wants to go.
When I take my kids, my extended family tends to tag along. We had so much fun our first trip with my kids many years ago that now, on the 'off' years when I don't take my kids, I meet up at WDW with those siblings/parents/nieces are able to make it. We pick a slow time of year if possible and those trips are shorter (5 days usually). Staying for less time and being able to share a room with another adult and split costs makes the annual trips more affordable.
I would say WDW is still pretty affordable for middle class families if they travel differently than I do: stay offsite, eat some meals offsite, pack snacks to bring with them into the parks, drive instead of fly (not easy when we're talking outside of certain states), etc. I know anecdote isn't data, but that's how many of my friends visit Disney now that I'm an adult living in the mid-Atlantic. They go once every few years. They drive. They almost always stay offsite. They might spend a week or more in Florida, but half the time is spent visiting other parks, attractions, beaches and the like. They don't do Disney the way I do. That's also the way we visited WDW when I was growing up (didn't stay onsite until I was out of college), and how the vast majority of my friends visited. The only family I knew who went to WDW at least once every year (they usually went more often) and stayed onsite were wealthy.
Personally, I think the ability to have an 'affordable,' lengthly stay onsite with free dining and great resort values was a short-lived matter coming out of the 90s, when WDW was building its onsite capacity (and the economy was booming) and especially the early- to mid-2000s, when 9/11 and the recession led to Disney offering huge discounts to get people into the parks. As a business, they're going to keep trying to make money, and so far, that has meant raising costs as much as they can...and if people are willing to pay those costs, they won't bring them down. That said, I don't think they can keep raising costs at the rate they've been doing without seeing an impact. It will be interesting to see if the lower-than-anticipated crowds with the Star Wars opening thus far continue past the early fall slow season.
, rather than what they can 'get away with'. The details matter.
