In his defense, he took over in 2007 right before the "financial crisis". Every other stock took a beating, and the gaming sector took a beating in the markets. They still have positive earnings. A lot of that price decline was out of his hands.
Contrast that with another gaming company, Activision-Blizzard, which has fared incredibly well during the turmoil since 2007 (and has paid significant dividends during that time)
I remember from a lecture at Gen-Con in the 90's that books and games do better during a financial crisis because they are more entertainment for the dollar. Maybe $60 video games don't follow the model.
That was a popular theory until 2008, when the industry was harshly disabused. I think it held so long as gaming was still expanding into the mainstream, but since the Wii/360/PS3 came out console gaming, at least, has been a saturated market.