Actually, FAIR does criticize these organizations regularly for being biased. It's just that the bias they see is towards the conservative side. These organizations are owned by corporations, don't you know, and everybody knows corporations are all rabidly right wing.
FAIR hardly ever seems to criticize anyone for anything. I get oodles of hard data from the Media Research Center proving liberal media bias every single day, but all I ever get from FAIR is one press release every three weeks or so.