It would make more sense if the switch was beyond the reach of anyone in the area and Luke used the Force to propel the skull beyond the barrier and hit the switch (Maul uses practically the same trick in TPM and it one of his few subtle moves).

It could then come down lightning fast like the Death Star door in ANH, the Cloud City gate in ESB and the Palace door in TPM.

While Luke could probably use the Force to bring the door down directly (Yoda does lift a whole fighter in ESB) it would be showy in a Count Dooku sense especially when there is a door switch to hand.