Somebody's gain is somebody's loss.
All the scam/controversies/blame-game etc aside. At a national level it makes sense only if bank is lending at say 10%, can they give you a deposit rate of 9%. If, for whatever reason if they are able to lend only at 8%, they of course will give returns of 7% on deposits.
Ofcourse that may not be the only way banks make money - but that is the reasoning behind the change.