It's all cool and awesome, but why put all those resources into new renderer, when one could contribute to Blender and such, which are way more mature?
Blender is not a renderer, it's a modelling and animation program with a built-in renderer, Cycles. But it can connect to other renderers, too.
Cycles is not that old. It replaced Blender's prior renderer just a few years ago.
I have contributed patches to Blender that got accepted. Even I feel the urge to write my own render engine, to try out different approaches and just so I can claim "I wrote that".