This is one of the biggest misunderstandings of the blockchain technology and distributed ledger. There has to be a single point of entry where the so-called Bitcoin blockchain updates every 10 minutes. True decentralization is not possible, someone has to centralize the data before distribution.
It is possible to update distributed records and aggregate them but this would be a cluster at best and definitely not something the financial world would be interested in. And no one in finance is going to even listen to a 50% majority rule if a blockchain is right. Just saying that there are master domains for blockchain distributed ledgers.