Thanks for your feedback.
This tool is exactly for developers. Of course there is some tooling for changing style of components in Structor, but it is not suitable for design — it does not cover all design needs.
The biggest advantage of Structor is in generating scaffolds of component source code (React, Redux, etc.) and pluggable presets of ready-to-use components on Structor Market (free absolutely).
Also, Structor is capable to extract components into a new presets which may be published on the market in GH repos.
My project does not have a good traction in React community so far. I guess it’s because I don’t have much time to tell about it everywhere, and the another reason — the lack of documentation.
Though, I have many feedbacks and now I’m developing Structor intensively. So, I hope it will be much more helpful to React devs, especially if there will be many components on Structor Market.