Yes, we'd all be better off if the short-long trade was outlawed and banks issued bonds on a liquid market, possibly insured by private counterparties, to their customers, instead of claiming that their money was available on demand. But nobody is actually doing that, or has any incremental incentive to adopt it so long as governments supply free insurance, and we have to consider what second-best options are available. Money has no intrinsic value (I assume we both take this as axiomatic) and the utility 'money' provides to civilization comes from increasing the number of positive-sum trades. When people attempting to use money as a guaranteed store of value keep that money instead of spending it, the velocity of positive-sum trades goes down. This doesn't mean that they're evil hoarders, though I do think that preferring money as a store of value generally indicates something wrong. But it does mean that supplying more money is a positive-sum move because it increases the number of positive-sum trades occurring, so long as there is significant unutilized capacity.