The difference is that Disneyland is a family trip that your kids will love and talk about for years. The whole Universal Studios and Knott's Berry Farm and all that stuff made for amazing childhood memories. Seaworld in the '80s blew my mind! Orcas are amazing (I didn't know about animal suffering because I was like 8 years old).
Casinos are weird. One generally loses money and, personally, I could never win an amount of money that could matter to me, so I would never bother. But that is just my opinion. Winning $200 or $2000 wouldn't allow me to do anything I can't already do but losing $200 or $2000 would feel stupid and terribly wasteful.