I'll upgrade my original comment: I think the business code is the present, and the abstraction is the wrapping. It looks pretty on the surface, and you have to do a bit of unwrapping to see what's actually there!

This is the likely cause - most software development is dreadfully boring. But at some point in a developer's career, they will have touched the monolith and everything is full of stars, and instead of saying "I'll just hook you up with Magento", they're like "I will build you an event-driven microservices architecture in a custom made C# framework" and disappear for six months while they work late nights.

(I wish I made it up. This was what a CTO at a previous project did. 30-odd people were waiting and churning on while he was unavailable because he had to indulge his own things. And once they were beyond the point of no return, both he and the manager that greenlit this project quit, but stayed on as independent contractors. I believe they were demoted or taken off the project and eventually gotten rid of when a new manager was found)

New life goal: become CTO.

This is a happier ending, could have been "he finished the project, it turned out to be bad but now everyone has to use it".

> I think this is explained by the fact that most business logic is dry

I don't think that business logic is dry per se. The problem in my opinion rather is that in other parts of the software project, there is much more openness with respect to

- trying out new things in new ways

- making the code more elegant

- seeking abstractions

- ...

than in the business logic area.

Believe me: for the kind of business logic that I see at work, I could immediately see ways in which the (non-trivial) business logic could be made much more elegant by using clever mathematical ideas, but suggesting such ideas to other colleagues or the bosses is like talking to a brick wall.

It seems to me that if you can see elegant simplifications (or really any significant improvements) but are unable to implement them, you are either positioned too low in the hierarchy, or in the wrong organization.