I would assume because usually very large roles such as custodial and even QSF&B have fewer available spots due to the size of the property as a whole yet they want to extend the opportunity to work at DLR to a similar number that's offered for the WDWCP. Remember that for roles like QSF&B at WDW you have the parks and water parks, WWoS, and pretty much every resort has at least ONE quick service location. At Disneyland you don't have this so they have to compensate by offering roles in other areas not normally available to CPs at WDW.