Soros is right. Nothing is safe - even gold. If you had put your money into gold any time between 1980 and 2000, you would have massively underperformed the S&P. Since 2000, gold has outperformed. I suspect this will continue for a few more years, but eventually, it will reverse again.
After all, what is gold really worth? It has very little actual purpose - it's only worth what people think it's worth. If you invest in gold, the value of your investment is totally dependent on sentiment. Stuff that is consumed, such as oil, base metals, foodstuffs, etc., has a stronger foundation. And even though gold has been in a 10 year bull market, most of the other commodities have actually done better.
There will come a day when it will be time to get out of gold. When it's on the mainstream news every day and people are lining up in bad weather to buy gold - SELL!