I never use the wedges on the green even although I know that, by using them, I could get closer to the hole in difficult or very long putts.
Someone said in another thread that players who use the wedges on the green, it is simply because they can not putt properly or not at all. It does annoys me very much seeing legend using the wedges in 15-20 feet putts almost every single green....c'mon at least try the bloody putt so you can improve your putting skills!
As for the video showing Phil M. hitting his wedge from the green, it is very obvious he could not hit the putt unless rolling the ball over the fairway. The only place I remember that players could find here in WGT in such situation is in St A green 17, but you still could try the putt because the green fades left towards the pin.
Whether with spin or not, same players will use the wedge anyways.