Actually that bank is mostly used in small towns where people have no option but open an account with them, that people from small towns probably have never heard of Bitcoin mainly because internet access in some areas in Mexico is almost non-existent or people just don't care about that and don't use it.
And if they had heard it before, they probably wouldn't change anything. Bitcoin would not be an payment option for them. The people there are certainly not wealthy and would certainly not accept $2-3 in transaction fees just to be able to pay with Bitcoin. People should stop seeing Bitcoin in its current state as a money substitute. It may be feasible for large-volume payment transactions such as trade between countries, but not for the little guy in the store around the corner.