My guess would be an attempt by the governing body to make "all things equal" weight wise. I don't care how good you are at rowing the gears, one of these days, you're gonna miss third gear at a very inopportune time. Sure, the auto guy can miss a shift too if he's got a full manual shifter...but not near as likely as the guy stomping a clutch and trying to hit a gate with a bunch of g-forces pulling him in the wrong direction.

Why do you suppose they didn't want any "robot" cars mucking up things in that race in the other thread?