What I meant to say was that this is the first time I came across a ledger use case specific DB, so I just coined that phrase, Domain Specific Database (similar to Domain Specific Languages).
And yes, you could say that the industry does suffer from some version of NIH. The concept of ledger after all is thousands of years old and yet software engineers don't bother to learn end up mucking up the implementation.
I attribute it to software engineers who are not willing to step back and learn the domain of money and payments. Whenever money is involved one should only have to look how professional accountants maintain their books and handle it, learn from existing products (such as Stripe[1], Modern Treasury [2]) before running off to roll out a half baked version of double-entry book keeping. The system kinda works initially but when the requests increase the errors begin to accumulate very fast and the businesses end up unable to trace millions of $$ or worse. I've seen it happen way too many times.
