Just because Disney to increase profits and that it might improve the guest experience doesn't mean it does. Not every idea is a good one.
Let's take a relatively recent example.
The problem: Disney buses were dedicated to a park/resort(s) loop. This resulted in many times where a bus would be running almost empty because there just wasn't anyone at those resorts at that time who wanted to go to that park but there would be some waiting for another park.
The solution: Put Disney buses on an open schedule so they would be redirected before each dropoff where they were to head next.
The intended result: People would be waiting less, buses would run fuller, and they wouldn't need as many buses.
Why this fails: The function they are optimizing just tries to minimize the total amount of wait time across all people. So if 99 people wait 1 minute less and 1 person waits 89 minutes longer, they have saved 10 wait-minutes. Sounds great unless you are that one person.
Before you could be assured that a bus would be along within 15 minutes (20 if you just missed it). With the new system, if your family was the only one wanting to go to MK while groups of 4-5 families kept coming out for AK every 10 minutes, your family would be sacrificed to keep waiting while each new bus arriving would be heading for AK since five families is greater than one. Eventually they would send an MK bus regardless but that is not what people expect or want. Now this isn't exactly how it works but that was the idea and the actual implementation didn't result in the theoretical optimal solution anyway so the new system is worse for guests. Maybe someone should have run the math that said "Even if we add more buses, the incremental cost of the bus is more than made up for the guests spending their time and money in the park rather than waiting for the bus."
FP+ has all the earmarks of unintended consequences that mathematically look good but guests' emotional human judgement rates it poor.
Yeah but that's the point of operations management, if you save time for more people than its worth it. If those 99 people are happier with their experience they are more likely to return and that outweighs the cost of the 1 person.
People all said the same thing about FP when it first came out. There were tradeoffs there too. In exchange for skipping the lines on FP attractions the standby times increased, but most people would say FP is worth that cost. FP dramatically changed the way people approach disney parks and likely FP+ will too. I agree that the touring plans designed to work with the FP system won't work with FP+ but that doesn't mean we can't come up with new touring plans. Most importantly, FP+ will allow disney to smooth out the flow of crowds in the parks which will benefit everyone...