you're not making money with gold. the only people doing that are the ones buying and selling it at the coin shop.
Gold is not going to make someone rich. How many people have you ever seen that say "investing in gold made me rich"? None!
People don't (or at least shouldn't be, as you've highlighted) buy gold to make money. Maybe silver has the potential to make money in an explosive inflationary scenario....however that's another topic. People buy these metals to store value, in the event that money is not worth anything anymore.
Gold and silver still have their place as store of value's. In the event that a monetary catastrophe happens, where liquidity dries up for all assets and the ability to transact digital currencies somehow becomes limited severely, these will prevail. Even when Bitcoin is not prohibited, these store of value precious metals will still serve as hedges against the failing reserve currencies. I believe that is their primary investment purpose, rather than trading for profit as you suggest.