MJG87

This is what I typically do after advice from my mechanic who is a good friend of mine.
It also has to do with perceived ownership and maintenance costs when people are considering which new vehicle to buy, who can offer the best "fixed price servicing" plans at the dealership, deals with fluid/component manufacturers etc. If someone sees a new car that needs oil every 5K miles and one that needs oil every 10K miles, people are more inclined to buy the cheaper to service, lower maintenance vehicle, and get a "cheap" fixed price dealer service plan to go with it.
10,000 miles (or 15000kms) is a common interval to see now. I used to do mine every 3500kms in my turbo vehicles. Driveline oils every 20,000kms. Sure it's expensive and time consuming, I do my own work, but it never let me down.

Its a machine, look after it better than you are "supposed" to and it will reward you, you can never look after your car too much.

For anyone who has't seen before,this is a typical Auto transmission, you can tell they need looking after and can imagine why they are more sensitive then you may think.