Why the bank would accept bitcoin sooner or later?

You must have at one time seen bitcoin service in most Automated Teller Machine (ATM) in some banks should you live in Nigeria in later year. But not anymore! Ever wondered why they ventured into that before? Could it be that they were optimistic about the potentials it avails or were just driven at the rate at which it rose in the market and how people patronize it?
Could it be that it was greed that drove them?
Would the banks accept bitcoin sooner or later from your opinion?