There are two ways to support a building with piles. You can go down to bedrock, or other hard material, or you can have sufficient and long enough piles so that friction holds things in place. In the latter case some settling is expected. But the settling in this case is more than expected. The building is probably perfectly safe in an earthquake. The problem is that if it tilts it will cause problems for the elevators and such. I don't think we will see any grand pianos descending abruptly from the upper floors but the units were expensive and I certainly understand the irritation of the purchasers.