Earlier quoted context omitted.
If the International perception of gold being valuable disappeared overnight (which... yeah, won't happen unless someone discovers legit alchemy magic) the difference between losing 90% of your value or 100% if it had no use outside of the speculation shouldn't be influencing almost anyones decision in what to invest in. All the other parameters (volatility, profitability, etc) are way more important than if you are…
My point is that gold can never lose 90% of its value because the majority of it is already used in luxury items and electronics. At worst, the total value of gold can only drop by the current amount that is being held in reserve or as investments.
--which is almost all of the gold in the world.