I knew you would bring again the argument of slipstream effect multiplier, tyre wear, fuel usage, things you can control in game but not in real life.
But there's a reason why DSP shouldn't be something considered to be controlled by the player. Because that is something which belongs to the car, more than abs, tc, stability. Even though some cars are really built to be used with abs.
So driving for example a GT3 car in game, you are simulating the car behavior from real life. Without DSP, you are no longer simulating the same things you can do with the car. So basically without DSP you can exploit the car in ways in which the real life driver can't do when he downshifts. But of course you could also exploit in-game tyre wear, fuel, and slipstream multiplier... but then should we ask the devs to make optional for GT3 cars the rev limiter, engine cut off, electronic kicker, maybe even ask them to give us the option to make the GT3 car manual transmission, exaggeration I know.