What? They do explain their results, and as you can see from the references section of any paper, other researchers read the published research and then build their new models using that information and continually refining the process.
Sure, they do their best to give an explanation after discovering it works, but nobody ever publishes the hundred other models they tried that don't work out.
This is a problem in most areas of scientific research. There is no incentive to publish negative results, so no one does.
Yes, they explain it, but in a very hand-wavey way.