Well, each resort isn't really operated as a seperate business, the resorts and the rest of TWDC are all much involved with eachother. If they were operated as seperate businesses, we would not be seeing two identical Star Wars lands, as well as other things. The profits from each resort are split between all of the owners, and each owner/company decides what to do with that money. Therefore, all profits that Disney makes from the parks (and other businesses) go into a big bowl, and part of the money from that bowl is going to Shanghai. I can't speak for the Shanghai Shendi Group and their interests.
Additionally, the money SSG (and Disney) pitched into the new Soarin film will help the domestic parks, places where SSG has no stake. That's why this short exclusivity deal is quite generous.
If revenue generated from one location paid for that location, then Disneyland Paris and Hong Kong Disneyland would be in quite a tricky situation. It's a very responsible thing for Disney to share money between different parts ot the business the way they currently do, in my opinion. Some WDW-only fans would disagree, but I think keeping the foreign parks running and trying to make them successful is the right route.
But you're correct on the second part which is more important. We would not be getting this film if it weren't for Shanghai.