I've been taken aback in the Bitcoin world just how many programmers do not understand double-entry accounting and don't implement anything near it in their sys

I've been taken aback in the Bitcoin world just how many programmers do not understand double-entry accounting and don't implement anything near it in their systems when they do any transaction that is not recorded on the blockchain (exchanges in particular come to mind). When you're moving around other people's money this is quite important.