The best and worst things that Disneyland did this century
Best thing? Kill the annual pass program.
Worst thing? Start the Magic Key program.
Disneyland is chasing dollars that it can't get from daily, out-of-town visitors because the park is filled with AP/Magic Key holders who spend far less per visit, even factoring in the pass cost. That has led to cuts in entertainment and service throughout the parks.
Dump APs and what happens? Prices fluctuate but go down on most dates while DLR adds entertainment and refreshes attractions to try to attract more visitors. Yes, the park takes a hit for one year while everyone adjusts. But it profits more in the long term. But Disney is not willing to take that one year hit, which is why this does not happen.

I don't agree. I think most of those APs actually spend far more money in the in end than any out-of-towner. AP's will enter the park just for a meal or a few rides and then buy a piece of exclusive merch on the way out. I hate the merch hounds profusely, but they definitely generate revenue that far exceeds what you would get from switching exclusively to day admissions. I think Disney's move to limit the quantity and devalue the lowest tier Magic Keys was needed to relieve some of the pressure off the park, particularly in the evenings, and the MK program has found a relatively happy medium to ensure the parks stay at or near peak capacity every single day of the year.