It is inappropriate to judge an animal by focusing on a skill which the creature does not possess.
A fish is specialized to swim superbly, and its ability to climb a tree is non-existent or rudimentary.
This quotation alludes to a long-standing allegorical framework.
In the domain of education this allegory has been employed repeatedly for more than one hundred years.
Hence, this quotation is built on ideas that have been in circulation among educators for many decades.
Along the same lines the narrative above on this web page e.g. the first and second sentence and the text in the picture is applicable to justice:
There is no point in finding fault where faults do not exist
(This is the lead sentence for the website).
Het heeft geen zin fouten te zoeken waar geen fouten zijn.
Il est inutile de chercher des défauts là où il n’y en a pas.