- Current bank owners (shareholders) should lose everything.
- Creditors should lose the necessary amount to save the bank, starting by those who accepted more risks (like bondholders) until those who did not accept much risk (depositors). Ideally, depositors should not lose anything or very little - but if the hole was too huge, they might end up with a significant cut.
- These same creditors should be rewarded with ownership of the bank. For example, if you lost 10K, and in total 10G were needed to save the bank, you now must own a millionth part of the bank in shares.
I can see no way to make it fairer than this. Tax victims should not have to spend a dime - that's externalizing a cost to people that had nothing to do it (imposed negative externality, moral hazard, private profit public losses etc). Only those involved with the failed bank should. Federal/national insurances of bank deposits are unfair by definition and should never have been created in the first place.
Insurance was okay when banks had a very limited set of things they were allowed to do. Now that they act as broker/dealers you are absolutely right.