In my opinion, it's very risky to backed any coin by gold nowadays. gold price isn't a stable at this time.
Following its logic, Bitcoin like other altcoins does not have the stable price, so you should not support "BTC and altcoins" due to the price risk being unstable?
Populous XAUP Token belongs to the class of stable coins for sure. It is not bound to USD or other fiat currency, it is bound to the physical price of one ounce of Gold, physical Gold was always the ultimate currency of last resort if anything else fails.
Fiat stable coins by definition will be always loss value per year because of systemic inflation. Gold will change in market-value but over the years get more value as it is not inflated like fiat.