Oh Disney could never give theirs away for free with a resort stay. Universal still sells many many express passes each day on top of the deluxe hotels. Disney would have to be money only.
Universal also has quite a bit of street performers, non-rides, and kids stuff to do, just like Disney.
Shows: Bourne, Horror Make-up, Blues Brothers, Beedle the Bard, Animal Actors, Celestina, Poseidon, Frog Choir, Triwizard, Dr. Seuss
Kids attractions: Caro-Seuss-el, Flight of the Hippogriff, One Fish, Pteranodon, Storm Force, Cat in the Hat, Seuss Trolley, Hulk, Minions, ET, Kang & Kodos, Woody Woodpecker
Characters/Streetmosphere: Minion dance party, Raptor Encounter, Dreamworks dance party, Scooby Doo, Marilyn Monroe, Betty Boop, Woody Woodpecker, Simpsons, Beetlejuice, Spongebob, Spiderman, Popeye, Cat in the Hat, Shrek and Donkey, Avengers, Fantastic four, Transformers, Doc Brown, ect.
Disney is certainly more family oriented, but it's not like USO is just a bunch of rides and no experiences.
If you want to make the attendance argument, Universal Japan saw more guests in 2019 than AK, DHS, and EPCOT. As far as I can tell they don't sell an unlimited pass, but do sell a once per ride pass.
Disney can absolutely sell this type of pass, but I'm not sure they want to. I think they want to keep it in reach of the average family to buy at least 1 or 2 days of their trip.