I think that they at least have to be open to the possibility of trying BTC,they don't have to use it but they have to make their choice.That's not the case right now as many people either don't know exactly what BTC is or have been given information which is not exactly correct and they haven't even considered using BTC.As to why they should use it,the biggest advantage of BTC is the flexibility it gives you-you can transfer any cash anywhere in a relatively short period of time without going trough third party