I never really understood the point of that.
Is it just so you can launch perfect everytime, so you dont have to get good at doing it the old fashioned way?

I can see how it would be useful in a F1 car, the last thing you want to do is stall without a starter motor onboard, and it must be hard with the super tall 1st, super touchy throttle, and on/off switch clutch. If you did it wrong you'd probably just burn tire way too much.