Because that solution would be just your favourite language and the next person would create documentation using your least favourite language, next person woul

Because that solution would be just your favourite language and the next person would create documentation using your least favourite language, next person would optimise the internals to be easier to work with their choice, next person would answer on SO using their choice, etc. Nobody stops you from creating the configs right now using your own serialiser, but having a common understanding of what's being read by the app and mostly talking about that format helps the ecosystem.