Octane's jump pad

So why is it that when you jump with octanes jump pad and you shoot mid air while you fly across the map that the shots you shoot spread out across all 3 maps. But when you stand in the air with horizon you shoot acectly where you aim? I mean it's already hard to aim while on the jump pad but than THISSSS!!! (PS4 player it's probably much easier to aim on pc while jumping but still you stand in the air with horizon and have all the time to aim and shoot)