Because racing in certain LoA sections doesn't exactly benefit anyone -

First to beat Atomos? You tend to step off your platform and stay off of your platform making it harder for the remaining parties to kill their Atomos.

Racing to kill the Batraals? That's cool, but that usually means you're ignoring your adds and thus killing off your two other parties and more than likely feeding the bomb too much and no matter how geared you are, constant add explosions ontop of the AoEs/direction attacks can and will kill off people pretty quickly if the healers end up dying.

I get what you're trying to suggest, but LoA really isn't the best place to reward people for speed running - SE got rid of Speed Running for a reason.