As the Apple reps have said, any aluminum coating can scratch off, it's just a property of the materials being used. You have three options:
1. Buy a good case
2. Be extremely careful with your phone
3. Accept that fact that your phone is going to get scratched and get on with your life. Scratches add character.
As an owner of two white iPhones, I can safely say that they are affected by scuff-gate, but not to the same extreme.
The white iPhone's rear casing does not scratch very easily, nor do the sides. However, I have had 2 separate scratches, which showed a slightly darker shade of silver. Using a chrome polish, it was possible to remove them completely.
One big issue is the chamfered edge. It is very delicate and extremely easy to chip/scratch.
Overall, the white model is better for long-term condition