I agree that the bike was eventually screwed by the control tyre which mainly became apparent in retrospect as you say, and the whole integrated chassis concept became completely unviable anyway when they brought in the engine number limitations.
Disagree about 2009. He had no dnfs that year (he had I DNS after the warm-up lap off in the last race attributed to a faulty tyre warmer) . He won Qatar handily, had competitive pace but not the physical endurance to finish races till his break, then more than competitive pace and no problems with physical endurance on his return.
You are in fact buying into the Ducati narrative which he has said both in his book and on other occasions was, along with I am sure the moderately widespread spitefulness towards him during his travails, the major cause of his disillusionment with both Ducati and the sport. He clearly believes his problem was mainly a physical one, and there is no evidence that it was otherwise.
I am a physician myself, and on first impression considered lactose intolerance a rather prosaic explanation, but it did eventually all hang together medically. If it was "stress", why did he have no physical endurance problems in 2010 when the bike was undeniably terrible and he was putting it down frequently?
