It will be hard to get 100 of the top banks to all put in 20 million in order to set up a new mining station/purchase already running ones. Some of them may have interests in crypto-currency (when crypto gets huge, there is going still to be a need for centralized services, and some banks are definitely looking towards creating a business on that, we've seen some exchanges from banks.

Sure, you've listed 10 or so banks that lose a shit ton of money. Can you do that with the other 90 or so banks? Do you think that every single bank will be able to reach a single conclusion, they all are extremely powerful and it's similar to how world-wide trading discussions fail. A crowd of people with huge amounts of power, means it's very, very hard to reach a single decision (even though it might be good for them all).

Just take a look at the DOHA round as a decent example.

Interesting thread, however.