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 but maths which is the bitcoin. its not stored in any third party service or by anyone else that can run off with it.

any crypto coin backed by an asset makes the crypto coin no longer the actual asset, but 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