Because a novel is about creative output, and engineering is about understanding a lot of rules and requirements and then writing logic to satisfy that. The latter has a much more explicitly defined output.

Said another way, a novel is about the experience of reading every word of implementation, whereas software is sufficient to be a black box, the functional output is all that matters. No one is reading assembly for example.

We’re moving into a world where suboptimal code doesn’t matter that much because it’s so cheap to produce.

The lesson of UML is that software engineering is not a process of refining rules and requirements into logic. Software engineering is lucrative because it very much is a creative process.