What are the father's main character weaknesses, not only morally or religiously, in the Wyss's The Swiss Family Robinson?

One would have to go beyond the actual words of the novel,
“The Swiss Family Robinson,” to see any weaknesses in the father, the main character of
the book. The way he is depicted by the author he is almost perfect; no, he is perfect.
He knows just about everything: what kind of plants and trees are on the island; what
kinds of animals live there; and last but not least, how to survive on the deserted
island. He is also the spiritual leader of the family, and is constantly giving sermons
while he’s giving out lessons on survival.

The main flaw in
the father is that he is too perfect.  He has no flaws that one can find in the book,
and that makes him a one-dimensional character, which you hardly ever find in a classic
novel.  “The Swiss Family Robinson” is a classic only because of the adventures that the
family has, not in the way that the author develops his characters, especially the
father.