When I first saw that oil change interval, I was kind of shocked too. I usually ride between 15,000 and 20,000 miles a year, so the long service intervals really attracted me to this bike--is there another bike made with a valve adjustment interval longer than 26,500 miles? I've trusted the manual before... When I took my bike in for its very first valve adjustment, it had almost 28,000 miles on it...and NOT ONE valve was out of spec (yes, most were on the tight end of spec, but EVERY one still IN SPEC). The Kawi guys have been at this game for a good while now: I could see this bike easliy going to 100,000+ miles with 7,500 mile oil changes and 26,500 mile valve adjustments without any serious engine problems....
Anyway, I think a lot of it has to do with how you accumulate your mileage. Motor oil likes to get up to operating temperature and stay there for a while to burn off some contaminants. If you just do a few short rides once in a while, changing the oil at least once a year might be a good idea even if you put in less than 3,000 miles. Same thing in reverse; if you ride fairly long periods (I've always thought at least 35-45 minute periods) and regularly, you can stretch the intervals. I also believe it has a lot to do with how important shift quality is to you as well.
Since break-in and the switch over to syn, I have been regular at oil and filter changes every 5K miles. My bike is approaching 45K miles and once I put the filler cap on after an oil change, I still don't have to take it off again until the next full change. I ride somewhere between 75-100 miles a day, 5 days a week, most weeks. When I change my oil at 5K miles, the oil (full syn Rotella T6 5w-40) definitely shows "use," but it is in no way what I would call completely used up. It still smells okay (unburned) and even has a hint of a (darker) honey color left...I can clearly see how someone could say that oil had another 2,500 miles left in it. By the looks of my 5K oil, I am sure it would cause no extra harm or wear to any part of the motor running to 7.5K with it.
The main thing I wonder about with Kawi's long oil change recommendation is shift quality.... My experience has been the shifting is "super slick" for the first 2K miles after an oil change (assuming syn oil), then goes to "pretty slick" from 2K to 4K, and then "semi-slick" from 4K to 5K. I can only imagine it would go to "less than semi-slick" from 5K to 7.5K. That's my main reason for changing it at 5K (and, as others have said, it IS cheap insurance--I only go 2/3 of what they say I can...). If someone really valued "super slick" shifting, I could see them changing the oil every 2-3K just for that reason alone!
Ride to live, live to ride.
2009 Kawasaki Versys
2010 Yamaha YZ 250F
2008 Honda CRF 450
2006 Honda CR 250R
I've owned a Maico.