3-hour one time events are NOT terrible...
It did change the world, the LA lighthouse was destroyed in phase I, and in phase III the karka cave was blasted open to make it accessible, while in phase II the entrance was blocked. Both changes remain, just as the lion statue in LA is still gone following the Mad King event.
But I agree, perhaps they could arrange the events so that the phases that change the world occur one time, and are followed by the temporary opening of an instanced zone for a few days, and completion of this zone results in the nice reward.
This forum is a wretched hive of scum and villainy. ~DevilLordLaser