Sure, it is an extreme. As in my edit I stated: this is due to sanitation. It is all over the board throughout the 15th-18th century world because pandemics/diseases/epidemics came and went and sanitation was so low and medicine was so bad that people dropped like flies, and thus did the life expentency average.

In particular, my “25 year l.e.” example was about 18th century France.