Certainly this could happen to any racer and we have unfortunatly seen it last year. However, the greater number of times you crash (especially in the first few corners) the greater the probability of getting seriously injured (by other riders as well). How many times has he crashed and (aside) DNF during a race???
Has not Marco had been warned time and time again by just about everybody there is - including fellow riders not only in private, but also in public? Yet, he would just arrogantly brush it off as nonsense regardless of who would say it. Needless to say, Marco had also been (rightly) critized for crashing or nearly crashing in the first lap and not as an isolated incident (just about everybody in GP has done so at least once).
YET once again Marco crashed in the first lap and rather than being ANOTHER boneheaded move in which he would simly return to the pits in shame and (perhaps) apologize to his fans.. and maybe having to put up hearing that "[marco] only has hair on his head".... (D. Pedrosa) instead due to bad luck, luck running out or whatever... it has resulted in this needless tradegy.
Thus, how many crashes, taking out other riders etc would have "required" a change of..... or perhaps you think that it is all just fine and dandy and should have continued with Marco's sucessful riding model???