Thanks for your feedback!
I guess you mean CSS-in-JS approaches where CSS is either put inside JS code as a template literals/string (styled-components, csjs etc) or as inline styles with JS objects (Radium etc.). Both approaches have their own advantages and disadvantages.
It could be only me, but I personally don't like the idea of having inline styles, although I realise it could be the only way to make styles cross-platform.
The string approach works well and has additional advantage of dynamic property values (in case of template literals). However, (and this is IMHO again), I can't say this is the most readable way to structure code, especially if you rely on IDE/text editor identifying this code as CSS.
There is a third approach, which is basically putting <style> tag right in JSX component, but this then gets repeated with every component you put on the page. Thus, I wouldn't consider this as an approach at all.
Let me know if I missed anything above.
My initial intention was to create a way to get styling and JS/JSX code together in one file in a way that would keep code readable and reusable.
This experiment does not tick all the boxes for the cross-platform, easy to write and read reusable way of combining styles and JS code in one file. However, the concept could be convenient in some cases where cross-platform-ness is not a requirement and styles are already written in CSS.
As I mentioned, one-loader was inspired by vue-loader, which I found convenient for the purpose of storing css and js code in one file.
Hope that makes sense