The day of the launch of iOS7, I warned my whole family in an email not to upgrade until it had some time to prove itself. This is why. Apparently it is a mess, at least for some users.
The sort of funny part is that they defend themselves by saying "at least it is not as bad as Microsoft OS launch." We certainly have latched onto a new form of accountability in the Obama age: "Don't criticize me because I am not as bad as the other guy."
By the way, as someone who is had been royally pissed off at Microsoft many times in the past, Microsoft has to accommodate thousands of hardware configurations and a much more loosely controlled development community. There are fewer excuses for Apple, which develops for a single hardware platform that it totally controls.
Also, there is one other difference -- when I am unhappy with a Microsoft OS, as I was with Vista, I can simply roll back to the previous version (in that case XP). Apple does not give users any way to roll back their iPhone OS.