Why does Vel'Koz R still use minimap targeting when other similar-ranged skillshots don't?

I'm talking about when you accidentally have your cursor over the map and it targets a point on the map instead of the point where your mouse cursor is. This often results in an ult going in the opposite direction of where you wanted it to go, which basically means certain death and an ult on CD. Try this with a normal skillshot, it fires towards your cursor and not towards a point on the map. Only some global skillshots behave like this. Iirc not even Xerath's ult does. So why does Vel'koz' ult, which is so short it doesn't even show a range indicator on the map, still use this way of targeting although it's completely impractical and has no use apart from costing you some games?