It's a nice idea but how would it be implemented?
There must be some way to work it out. There is already a crypto XNF-NoFiatCoin which is working on the idea.
See, There are sets of people who never accept bitcoin because its not associated by something real or tangible or some organization. Every now and then we hear some negative news with respect to bitcoin. So, I believe it would be a fantastic idea to make bitcoin settled permanent by backing it with something like bullion just as in case of XNF. Gold has always pulled people and considered as a safe investment. So backing bitcoin with gold will be boost the confidence of people.