Because you only spend a tiny proportion of the race holding the "starting handles", so comfort is irrelevant, but they are hanging out in the breeze the whole time so putting them horizontal minimises frontal area and therefore aerodynamic drag.
but if you placed them facing upwards wouldn't they produce lift, making the bike lighter and cancel out any negatives of aero drag?
but if you placed them facing upwards wouldn't they produce lift, making the bike lighter and cancel out any negatives of aero drag?