[Command] - "/spawnpoint" and "/setworldspawn" are Not Compatible with Rotation Parameters

As of Minecraft version 14w07a the "/tp" included the capability of adding rotation numerics. For example Each time you execute the command "/tp <target | player> <x> <y> <z> <x rot> <y rot>, you could have the player face a certain direction. (In this case north, towards negative z) However, the "/spawnpoint" and "/setworldspawn" commands do not allow for those parameters to be executed with the command itself...