Desmo service isn't necessary for majority of owners. Everything typically is within spec when some have had the service done.
I'd say if it's ridden really hard and has actually reached the 15k mileage mark, then it would be a good idea to do so. I don't intend on doing it. Mine has never seen redline or 6th gear for that matter. I'm 99.9% certain mine will still be within spec, 10years later when i actually hit the 15k mile mark lol. 7 years in, 6000 miles.