"This action effectively means the $250,000 FDIC limit is meaningless: all deposits in any bank are presumably insured by the full faith and credit of the United States."
Exceptional circumstances sometimes call for exceptional measures. A bank with 85% of its accounts over the $250k limit where most of the depositors are contractually locked-in companies is not normal. Moreover the contagion nucleus in this network were a few culpable super-spreaders with exceptional power. Other banks don't face that threat either.
Banking policy must be written to include exceptional circumstances, but the idea that all banking policy needs to be rewritten to burden smaller banks with situational precautions which are impossible for them to encounter is dangerous idiocy. Don't write housing codes that require 9.0 earthquake tolerance in areas primarily hit by hurricanes!
Furthermore it's dispiriting to see generous tit-for-tat given such a cynical portrayal. If two people have knives to each others throats you don't win by just not being the first to cut, you win by putting the knives down.
This situation was exceptional, and the panic was triggered by people with outsized network influence who should have known better. So maybe, just maybe, we deal with the reality of the situation rather than assuming it must be a harbinger of total change.