In chinese medicine they seem to emphasize the stomach and spleen/pancreas or digestion but I suppose this includes the livers digestive function Perhaps this is because they eat a low fat low meat diet anyway. The liver is more emphasized in western countries it seems due to the diet history.
Also you can be born with a weak anything. Maybe your can be born with toxins from your mother but also I think as chinese medicine says blockage in energy flow can deprive any organ of energy and weaken it. The liver is usually regarded as a problem if it is too
full rather that weak in TCM. I think some naturopathy ideas are a bit out of date. They come from when our diet was a bit different. All organs I think need to considered equally