Why would a country build its own card payment provider instead of using Visa/Mastercard/Maestro?

Most countries are now supporting or leaning towards the idea of a localized payment system, one that is free from Interchange fees as imposed by VISA and/or Mastercard. The reasons are plenty. The network they already used is laid out. Only a back-end switch mechanism needs to be placed to understand the 'domestic card transaction'. For developing countries, no matter how small (or large), they do not want to see their foreign-exchange exiting the country that is accumulated on Interchange fees.

From a user's perspective, the arguments are really strong:

• 99.5% of the population is not travelling overseas!
• I am local, my bank is local, the network (physically) is local, my money is local, so why cannot by transaction be local? My ATM transaction is certainly local, so what stop the POS transaction from being a localized transaction?
• Why should I pay X% to VISA/Mastercard, when the entire eco-system of my transactions is within the country and not going being routed abroad? Surely we have smart people who can make and distribute a card that is localized.

Central Banks are now promoting localized payment systems as it fosters more competition, growth and provides a competitive playing field for the payment providers to compete for the end-user's business. The model being followed by most is that of a an "Alliance" model, where multiple Banks and other FIs cooperate and come under a single-brand umbrella to offer the collective power of their payment network for localized payments.