Central banks are more fragile than the Bitcoin network and they definitely don't have the support of the masses. I expect they would lose a lot more than just money in this attack.

Bitcoiners would love to pull these institutions out of the shadows and I don't think central banks survive when exposed to sunlight. Just a small community of coders caught wind of how CBs operate and constructed powerful platforms to carry out large scale speculative attacks on them. Imagine what happens when a few billion people understand how CBs operate... their days are numbered.