The transition to Vista - in reality - may have been to a very large degree devoid of the pomp & pageantry that M$ is pretending to lay claim to from their sales figures, but that is not enough evidence to mark the product as inferior to XP.
As we all know - a bad move at the right time isn't usually as foul as a good move at the worst possible timing.
IMHO, a big part of the reason why Vista's few flaws are hugely magnified is that the product took way too long of a time to make it out of Redmond's laboratory - all the while allowing people to get almost too comfortable with the well cured Windows XP. I honestly do not think the reception would have been the same had Vista debuted say three years earlier than it did.
Now, are there problems with Vista? Yes .... Are they serious? A couple or more seem to be. Are these issues as monumental as being portrayed? I don't FINK so.
Controlling for the time period between 9X & XP and the magnitude of that launch's receptive outlash & doing the same for XP & Vista - I would say this is to be expected because it is once again a phase the will fade away in due course as Vista gets fine-tuned.
I don't expect the transition to be smooth for 100% of folks making the switch. A few are going to hit that rough patch but most should sail through with the least amount of displeasure.