I think it's popular in the manufacturing world now to tout long service intervals. All about cheap cost of operation. A lot of new cars/trucks have a computer system to tell you when to change. Friend of mine's wife ran her car 23K miles before the computer said to change it. The verdict of whether that's logical or not is above my pay grade.
I don't think you can discard the time thing. For example, a business use tractor could clock 300hrs in 6 weeks. Or as "Fried" said he puts on 10hrs per year. Which tractor should adhere to the clock hours? Even if Fried changes at 100hrs it will take him 10 yrs to clock that time. Is it okay for him to only change his oil every 10 yrs? Or in the sense of the business machine with an owner that thinks he needs to change every 100hrs, he's changing every 14 days. Which is most logical/illogical??
If you are putting your hours on steadily and relatively quickly, stretch the hours a bit. If not, compress the schedule.
Not sure if I ever heard you say how many hours per year you clock on your tractor?