Essentially, you've just found another way to rephrase the tired old cliché that Bitcoin supposedly isn't backed by anything.
I don't think that this has anything to do with the existence of Bitcoin. It is indeed, like gold, not backed by anything.
You people are full of imagination. Bitcoin does not represent debt like dollar. There are no debtors, creditors, loan contracts, or collaterals. Bitcoin is imaginary. In your wallet you hold a number that quantifies imaginary bitcoins. That's all. Watch the video again.
You're closed minded. In our wallet, we hold private keys which can be used to sign transactions. There's no reason to think that the number of an output quantifies anything. It's just a balance that increases and decreases based on the transactions you sign. If we all agree that we could debt each other using that number, why should you try to stop it?
I'm still waiting a valid answer to this:
You should picture it in another way. Imagine a 3D printer printing tangible items called “bitcoins” every 10 minutes and whoever was near the machine could earn them. If some people (bitcoins' owners) started using these coins as a medium of exchange, you'd say that they do exist. What exactly would it change if instead of tangible items, we had a public ledger showing who owns what and that we knew that this ledger can't be censored or erased by anyone's will. It'd not make bitcoins non-existing, but rather intangible. And that's because that ledger wouldn't show an IOU, but a strong proof that you don't owe me anything. You paid me.