I was reading at this Milan forum in the Pirlo thread to see what people think and I went back to 2009 to see what people thought of him and to my surprise there was a lot of people who were hating on him even back then, calling him overrated and stuff. How come? acmilan, tell us more.
it's something normal for fickle-minded fans when the team isn't doing well - they needed someone to blame and Pirlo, along with gattuso, Seedorf, etc were the targets.
It's ture, to an extent, that Pirlo did look sluggish and lacking motivation after 2008 but it wasn't because all of sudden he became a bad player but becuase he was simply caught in the general apathy at Milan in that period with Kaka getting sold, Carlo leaving, lack of proper reinforcements and investment in the club in general and Milan falling off as a premier club in Europe, etc.
Anyways, what you read had nothing to do with Pirlo losing his qualities as a player, just knee-jerk reactions by frustrated fans, as Linebreak mentioned.