There's really no need to restore all of the Great Wall (nor is it even possible). Restoration means making it palatable and accessible to visitors, which is simply unnecessary for 90% of the Great Wall, since they are located on extremely difficult terrain.
The repair work mentioned above might be poor in aesthetics, but it serves the practical purpose of keeping that section of the Great Wall from crumbling.
In fact, some sections of the original Great Wall are now nothing more than an eroded earthen rampart.