the same reason why the BMWs are speed limited to 250km/h. : For you own safety
If your superdrive would really act like a "superdrive" you could stat ripping dvd like there was no tomorrow, pirating all you DVD collection. You would be copying 6 DVD per hour 24 hour a day. You would nee to buy 4 1TB external drives every week to be able to burn the the 1000 movies at full resolution for that week (4GB per day).
After two weeks the police would find out and would raid your house and find 2000 pirated movies....
You will go to jail and have a hefty fine
Enough with the joking, If you say that you want to rip 2 movies per month, and you say you have a girlfriend: Well use those 80+ minutes of ripping to spend some quality time with your mac and away from her...