Only when things are actually his fault. His criticism is well deserved based on his prior seasons and a good chunk of this one, before he was taken off the top pairing.
JVR is mainly the scapegoat this year.
I do think Carle has always taken an unfair amount of flak though, Coburn (for example) doesn't make the giveaways because he doesn't make offensive plays (and hence gets far fewer points). Also Carle isn't physical, if he was hitting people left right and centre we'd be all over him. You need to have some puck moving D-men and he's good at what he does, he's not good at playing a physical stay at home type of D... He's never gonna be an elite guy but it's shown that with the right partner he's been pretty good.