>it will improve the quality of the code
That does not mean the product becomes more useful. I could rewrite Windows 1-to-1 with better code quality and no one would care because it still provides the exact same features. Unless "better code" means "better features", better code is useless.
Better code allows you to write new features with less risk to disrupting your current features.
Software design and architecture is about creating a system that can be built well, run well, and modify well.
If you just throw things together without thought you get an unmaintainable mess.
This is extremely short-sighted. Software is not a static product. "Improve code quality" translates into being able to add features more quickly and with less risk of bugs. For an open-source project, this also gives readers the opportunity to understand the codebase and learn from it.