Red's author here. The answer to your question is, I think, that it is just not ready for prime-time yet:

* Language and runtime library are at version 0.6.4, so still alpha stage.

* Lack of support for mobile and web platforms (Android support is coming this year).

* Documentation is largely incomplete, still relying on Rebol docs for core parts.

* Community is very active, but still tiny, it needs to grow much bigger.