yeah, i have had many people say that they might screw drifting up like in need for speed underground, that drift mode was hilarious! but i think they are smart enough to make the mode good, they've had alll this time to perfect it anyway.
but the point of getting 100% in gran turismo games is to learn all types of racing, you learn how to drive ff's, and fr's and all kinds of others, so i think they would want you to leanr to really drift and really know how to do it.