Since most of us on these boards are "Disney Addicts", we can talk about not going to WDW because we dislike the changes they've made. And yes, at some point, Disney will begin to miss the money from the AP clients, the Vacation Club people, off-site guests and other repeat customers. But I think we're forgetting about the people who are there for the first time or come only once or twice a decade. Will these people even know about FP+ before getting to the parks? I doubt it. Think about their experience now - longer SB lines in previously walk-on attractions, more people milling about making the parks seem much more crowded, and getting on fewer rides. AND IF they know about FP+, their first experience might be the long line at the FP+ kiosk. I don't think these people will become repeat customers either. I do believe that at some point in the future, Disney will see a decline in attendance.
Also, let's talk about word-of-mouth. Since I hated my last trip last year, when friends ask me how the trip was I tell them about the changes and what it's now like. I can honestly say that at least 10 or so families decided NOT to go because of what I told them (and they were repeat visitors-going about once a year). They decided they could get more of their money's worth going elsewhere - and besides, there isn't anything new to see.
When will this begin to affect Disney? Who knows, but I think it will soon.
I've had the exact opposite experience. 2 families I know recently came back from their first trip at Disney. They both stayed on site and therefore knew about FP+ from the mailers Disney sends. Both families thought it is the best thing ever. They don't know that the Pirates line is longer than it should be, or that waiting even 10 minutes for Figment is absurd. They got to take pictures of their kids with princesses and and go "into" their favorite movies. That's what they remember from the trip, not whether or not they "wasted" a FP+ on Buzz's Space Ranger Spin or passed up BTMRR because the line was longer than they wanted to wait. Both of them have already booked trips for next year.
Secondly, I've had a few friends and family members talk to me about a potential Disney trip. I'm honest in laying out what FP+ does and the gigantic time investment it involves, how you need to stalk
MDE for the right times, get up at midnight and still miss out on things, etc, and also the realities of what they will face in the park if they try to get day of FP+s. All three are still going, and 2 have switched their plans from off-site to on-site to get the 60 day advantage.
I think that's a key piece of what a lot of the FP+ threads are missing... I think Disney is willing to sacrifice some of it's regulars (who probably don't spend as much as first time and potentially one time visitors) to have first timers and others "locked in" in advance. It does make it way more difficult to wake up and decide to go to HS instead of AK now, but it also makes it way more difficult for people to wake up and decide to go to Universal or SeaWorld instead of AK. And that, in turn, makes it easier for Disney to plan their staffing, park hours, etc, which means greater profit. Plus, now they are collecting all of this data on what people like, how people move around the park, how much and when they spend, etc. I'd bet my own paycheck that that data is going to mean money in the future.
We could debate all day about whether Disney having that data is beneficial for us, or whether FP+ is good for my family or your family, but I don't think there's any argument to be made that it's not good for Disney's business. And unfortunately, that's going to be what operational decisions are based on, not the experiences of individual families.