When you take millions from your employers to do a job you ride as hard as you can no matter what point in your career you are at.
Like I said, Stoner had basically no reference point when he jumped on the Ducati so he rode it the way it needed to be rode. Rossi being on Japanese bikes for 9-10 years knows what those bikes are like and what a good bike is supposed to feel like so why would he ride the ducati like Stoner did when even Burgess admitted that Stoner basically almost had a crash every lap.