Epcot doesn't have a billion dollar budget. Maintenance at Epcot certainly doesn't have a billion dollar budget. They weigh what's most important to the show, as you say. The fountains? They still work. Is it worth the time and expense to drain them, rebuild them, retime them, etc? It's not a simple task -- that's weeks of work, minimum. If your maintenance budget has X amount of dollars and you need to decide which is most important, a still-functioning fountain or one of the only rides in World Showcase, which is visibly falling apart... I'd choose the ride.