You would have to assume in this case that all banks perform the same screw-up and lose investment bonds/funding in the same fashion. The odds? One in a million. What helped the case in Cyprus is that you only have a few national banks. Every single bank president knows his other associates on a personal level, and probably knows the national political apparatus on a first-name basis. Whoever dreamed up the idea of buying Greek bonds at the worst possible time, and then convinced almost all of the banks in Cyprus to do the same thing....deserves fifty years in prison (my humble opinion).
All bank insurance situations are geared to help the little guy only. You can’t find any country in the world which puts out a million dollar limit on FDIC-like insurance.
As for the term “tax”? The journalists have attached themselves to the term, but I doubt that the official paperwork to each “loser” will say the word tax.
It wouldn’t have to be every bank just say the top 5 or 6 and we pretty much had that when this whole can of worms started. And it isn’t just the journalists using the term tax. The FDIC has been all but broke a number of times. With the exposure to European derivatives that the biggest US banks are exposed to if Europe folds many a large bank is going to take huge hits wounding them most like beyond saving.
You are implicitly assuming bank failures are independent. When you get a run on the weakest bank, some savers at the second weakest will panic and withdraw their money, which can bring that bank down . . .