What important is the number of independent nodes controlled by different entities, especially if those entities are active users (which includes services, hodlers and just people who use it as a currency).
That goes up for blockchains aiming to be decentralized. In this case it's just MasterCard hosting nodes in different states/countries to maintain and solidify its centralized blockchain network.
Blockchain is important because of its game-theoretic properties, I don't think it's that great as a single-user database.
Your view on blockchains is way too general. It's not that every blockchain by default is the same as the other, even though they from the core have the same foundation. If you want, you can shape a blockchain into any form that suits your needs, and that's exactly what governments and financial institutions are researching and developing. Ethereum as foundation is a great example of what potential centralized incentives could look like for financial institutions, and potentially even governments.