I always name or link to sources, however in this instance it was a meme-type image which was self referencing and explanatory.

Did you not see the line, "LTC David Grossman in his book On Killing", at the base of the image?

I figured that was enough source because we all know how to do a Google search for "LTC David Grossman in his book On Killing".

All I did was search that sentence online to find the image for you, plus it's easy to then search for the book as well.

I do agree with your statement and its sentiment.

Having been a teacher, plus having 4 uni degrees plus being a fully trained librarian, I am always super conscious of referencing sources.

The image itself carried the source in this instance.