If that was the case and they didnt have the spoilers armed then why go all the way to touchdown before going around?
The spoilers did deploy, meaning they were armed. They will retract again according to certain conditions (on the Airbus, moving any thrust lever above 20deg, I assume something similar on the 747) - i.e. initiating a GA. The fact that the spoilers did deploy means that the thrust levers were at, or near, idle at touchdown, indicating the GA was not initiated until after touchdown and bounce.
Wouldnt it be more effective just to do a normal GA?
They did do a normal GA. Select TOGA, hold the pitch attitude til clear of the ground and fly away. Bounces can happen, perfectly normal. This crew demonstrated textbook decision making and baulked landing technique.