What makes a park a full day park isn't the quantity of experiences. A park could be packed with spinners, flat rides, and meet and greets. For someone with toddlers and young children, that could occupy a full day, but for most visitors, they would find themselves bored after a few hours at most.
No park is designed for guests to experience every single experience offered. You know that some people may not enjoy Great Moments with Mr. Lincoln while they may appreciate the Storybook Land Canals. Some may love Tron and you couldn't get them to do Belle's storytime experience to save their life.
What makes a good full day park for me is if there is enough variety to allow me to have a lot of varied experiences throughout the day. I can spend an hour or two riding the pretzel rides and enjoying their charm. I can spend several hours on the giant E-tickets that immerse you fully, I can spend an hour experiencing Fantasmic or a quality stage show, etc.
Considering that the Gumball Rally exists and people routinely can knock out all or most of the attractions in a single day, I would never call Disneyland a multiple day park. It's just a really good theme park. Single day, but full of so many types of experiences. You could do all of the DLR in 2 days, including DCA. If the Florida parks were closer to one another, I could easily do MK, DHS, and AK in the course of a single day.
Epcot is the only other US Disney park where I have to spend a full day there to experience all that I want to experience.
