That's not fair, most fans of most clubs are like that, when Fergie loses 2 games in a row there are grumbles, Chelsea fans are griping about AVB. Most fans keep the faith though.
Also, how good are Giggs and Scholes? Both over 100 years old yet they can still score goals and win crucial games.
It's entirely fair! Much as I'm not a fan, Wenger has earned some leeway from Arsenal fans but has been getting absolutely pilloried the past few weeks. You can't really bring Fergie into it because United fans may grumble but would never dream of calling for his sacking. All the Gooners I know (and I know rather a few, North London boy that I am) have been hideously unreasonable about their manager lately.
Also: Chelsea fans ALWAYS have ideas above their station. AVB is on a hiding to nothing, bless him.
And you're right about Giggs and Scholes, of course.