In all the article, no reference to the business those abstractions or duplications are made for. I mean the way to decide if it is a "good duplication" is to a

In all the article, no reference to the business those abstractions or duplications are made for. I mean the way to decide if it is a "good duplication" is to ask ourself if it is a coincidence that it is the same code: 2 business rules having the same implementation does not mean it is a duplication.