Should auto cast for spells that buff players be added?

Right now there are almost no spells that would benefit from auto cast other then Plague Riders Cursed Shield and Ice Orges Frost Shield however these spells would be a lot less painful to use if they auto cast on all near by heroes who did not have the buff and never cast it on creeps. Adding a feature like this would also mean it would be in the game for any hero they add to take advantage of.