I also sometimes get the feeling, that anything but a win* in any race he competes is a disaster for his fans and also for him. Sure, call it winner mentality or whatever, but I think it would do some good to both the fans and him, to regard his results as good, sometimes even amazing, even if he doesn't win everything**.
With regards to the argument, that even if he was mildly ill, there was no point to wait for a possible partial recovery and still try to compete for the best possible placement, even if it is very likely not to be a win.... There should be no shame in finishing top 5 or top 10 in the Giro, it's not like he has that many GT results to act like they are not worthy of his attention.
If on the other hand, he really fell (not only mildly) badly ill from the time of first checkpoint till the evening (which was not the message), when the decision was announced, then sure, he probably shouldn't ride the very hard second part of the GT.
I mean, in all ways the decision is his and of the team, but I think that they always disregard anything but a win in their calculations, which can have many consequences, few of which seem intuitively good.
*or close enough to a win, that one can argue, that he was "the strongest" anyway (catalunya, etc...)
**or isn't regarded as the best of all, no debate about it