People believe bitcoin is backed by nothing. I think that is not the truth. I believe bitcoin is actually backed by people themselves. It is backed by none other than just you. We all witnessed the price has been fluctuating by all those FUDs and bad news. The price changes by emotion and non logical facts. I believe you hold bitcoin no matter what happened and would happen, and believe it is backed by all of us, it would make a history. 
The real question may be whether currencies being gold backed collateral can function as a preventive measure to mitigate the risk of dangers posed by overprinting or hyperinflation based crashes fueled by state issued deficit or debt. Gold backed currencies like the (geman) deutsche mark have hyperinflated and crashed in past history. Gold standards were largely being utilized before the advent of the internet, digital currencies or the recently proposed "cashless societies"(which are the furthest thing from being gold backed or NOT creating money out of thin air
).The concept of "gold backing" being a valid protection scheme against negative consequences could be archaic or obsolete. Gold standards were devised long before the internet existed. Long before credit cards or modern day conveniences. I think civilization might benefit from greater acknowledgement of "gold backed" securities no longer fulfilling their intended role.
If I did not name any spheres, then maybe someone else will add.