Letting banks fail when the country's economy is in a crisis is not a good idea. So I am not surprised by this.
While Russians might move their wealth out of Roubles into other currencies, I think what matters is the ease of movement. Would it be easier to buy USD for roubles or easier to buy bitcoins?
This is true. Banks' health is very important to a country's economy as without healthy banks credit will free and the lack of a credit market will cause economic activity to slow down.
It is a generally good economic policy to only let banks fail when the economy is healthy and can absorb such a shock (especially when preventing larger banks with a large economic footprint to not fail in times of economic crisis)