There are a lot of pros to being a developer who dabbles in design.
- When you demo functionality to a stakeholder, what you are demoing and what they think you are demoing are two separate things. Knowing how to make a partially-complete demo look presentable prevents them from focusing on the unfinished design work that doesn't matter at that stage.
- As a developer, you know the limitations of your architecture. When resources are scarce, there's nobody better than you to weigh the cost of the time to build the feature vs the visual benefit of having it there.
- Some design work is discretionary and some is common sense. Understanding the common sense parts means you don't have to be told every little thing you need to do when building your front-end. That means there's less time wasted in back and forth dialogue.
- If you can put up an initial design, you don't need to wait on somebody else's timeline and priorities to deliver an MVP.
- You get variety in your work, which is a nice thing if you're feeling like a code monkey.
While these benefits are universal, they are especially important when working fast, and when on small teams. They also apply to designers who dabble in coding.