Fair enough. Servicing costs are higher in the UK (far higher) but we serviced cars generally once a year. Out here we're asked to service cars every 5,000km, which is about four times a year. So on a year to year basis it ends up costing just about the same.
Service interval in Europe is indeed higher, 20.000 km or 1 year at least for the small cars and up to 40-60.000 for the long life service interval german cars like audi, but it's very different climate conditions.
Here the road is very dusty, both for the desert and because it never rains so it stays there (you can see that the amount of sand going around the engine in two weeks is more than the dirt it goes in my engine back in europe in 1 year) and the temperatures are extreme also, so I understand why you would want to change your air filter and oil every 10,000 km. The decay of the oil is faster here.
As far as I know only toyota is reccomending also "minor" services every 5,000 km here, do you know of other brands ? Ford is every 10,000 km for example, and I think also Chevrolet.
I am pretty sure this is just to optimize their cash flow anyway rather than by strict technical necessity ;-) my rental yaris (1/2008) has 120,000 km, looking at the stickers on the door has been serviced grossly every 10,000 km (not at the dealer) and does just great (mashallah, touch wood ;-) )
But if you're going to resell your car a lot of value - at least for car that you buy new and want to sell after 2-3 years - is in the full service history at the dealer, so you have to do your math carefully to see if it's better to service at your convenience, or at the dealer.