There's just no basis for saying that. Foligno's raw corsi was 48.1%, that was 12th best on the team (top ten if you take out Kloos and Belpedio). Obviously he didn't face the competition that Koivu did, but he had a higher relative corsi than Parise, Coyle and Winnik. He had the same fenwick as Suter, and again a better relative Fenwick than Coyle, Parise, Winnik. Stewart was awful by those metrics, but Foligno also outscored him. 5v5P/60: Foligno: 1.49, Stewart: 1.42 (same as Cullen).
Like, you might think he makes too much money, but he's relatively effective at what he does. I'm not a huge fan but you don't win games by having a bunch of terrible players making league minimum and doing worse than that.