I’m not an expert in physics but I think your question comes down to common sense. Please correct me if I am wrong.
Rolling the bar towards yourself would produce momentum on the horizontal plane. The more weight you have, with the more force you have equals more momentum.
If anything I could almost seeing this harder to lift vertically as you would have to fight the horizontal force. As the previous poster replied, it helps them push from the heel. Personally I just curl my toes upwards before I lift as I find rolling the bar messes up my form.