Pietersen, who was axed by the England and Wales Cricket Board (ECB) in February after Alastair Cook's side were thrashed 5-0 in the Ashes, has hit out at a number of England players and staff in his latest autobiography.
Wicketkeeper-batsman Matt Prior and former team director Andy Flower have come in for particular criticism from Pietersen, whose revelations regarding an apparent bullying culture within the England team continue to attract particular attention.
Discussing the topic at a Hardy's event at Lord's on Thursday, Anderson is quoted by the Guardian as saying: "The issues that have been brought up are sad really.
The seamer added: "The dressing room for the seven or eight years we were winning and successful was fantastic. You don't achieve what we did during that period without all the guys pulling in the same direction.
"I can't get my head round it. He [Pietersen] seems like he has not enjoyed it for any of the time he was there, but we all enjoyed it."
The fall-out from Pietersen's book appears likely to overshadow the England team for some time to come.
"I'd like to think they [issues in the dressing room] could stay in house," said Anderson.
"This is not an ideal situation but it's different with Kev. He never got a chance to stand up for himself in the dressing room because the opportunity to be in the dressing room was taken away from him by the powers that be. He is now venting his frustration through a book."