Thats's not perfectly illustrated at all...financial institutions have been capable of servicing transactions 24/7/365 for decades now. ACH just doesn't do it, and a blockchain doesn't inherently empower it more than, say, Postgres.
...which is precisely what perfectly illustrates the problem. Users are at the mercy of some arbitrary policy of not processing transactions on weekends & holidays.
That's not a technical problem, especially because every blockchain proposal for financial institutions is centralized. Until you hit competitive transaction throughput on a blockchain while retaining its decentralized features, it doesn't really free you from being at the whims of other parties. There is no proof of work or proof of stake system that solves this yet.
That's the point: it's a human problem. And by removing the human element, blockchains solve the problem.
Note that I'm taking about decentralized blockchains (Bitcoin, Ethereum...), not the private centralized ones that are being proposed for financial institutions.
