To add, what makes the business logic so painful is that you don't define the rules yourself. They are the result of legislation, regulations, lawsuits, contra

To add, what makes the business logic so painful is that you don't define the rules yourself. They are the result of legislation, regulations, lawsuits, contracts, and preferred work processes of very headstrong individuals. The codes tries to reconcile all of that to get to a solution. It's not about a great idea, it's about the laws of physics being written by a committee.