Alright, time to bust a myth. As an AWD owner, every time I have a tire issue, they tell me I need to replace all 4 even if the others are good ... because AWD

Alright, time to bust a myth. As an AWD owner, every time I have a tire issue, they tell me I need to replace all 4 even if the others are good ... because AWD. "Won't someone think of the tires ... the tires need to to be the same size so they can rotate at the same rate." Clearly, with AWD the car is designed to allow wheels to rotate at different rates (hence the diffs). Otherwise you would't be able to make a turn. Once you dispel that myth, they then tell you to replace the pair ... Why do dealerships, repair shops and tire places keep insisting on replacing all 4? ... good for tire sales I guess.