bitcoin needs backing by nothing.
if i want to invest in an asset i want the asset, not a IOU voucher, receipt, certificate that represents the asset whilst someone else physically holds it.

EG mark karpeles
while people played on his exchange pressing buttons and moving SQL database balances (IOU's which get redeemed for real bitcoins at withdrawal). karpeles was saying all the proper bitcoins were in cold store...... look what happened.

the bitcoin i own is in itself the asset, backed by nothing. any crypto coin backed by something else is not an asset, it is simply an IOU, which gets redeemed if you ever get to have an agreement that you have the real asset delivered to you.

we need to keep the crypto technology out of the old IOU game