It's a much clearer explanation than the original post, because it explains a different concept, which is easier to understand than the content of the post (what does a tensor product of vector spaces mean?)
The distinction is between understanding an instance of a concept (stress is a tensor) and the concept itself (what is a tensor, i.e., what exactly is it that stress shares with all other tensors). This is why the explanation in terms of a universal property is more difficult to understand: because by virtue of stripping away the extraneous details, it shows you the concept as it applies to all instances of the concept.
As someone who had no idea what a tensor was, a rough explanation of what they might sort of be related to is better than something that I don't understand at all, as long as it's clearly labeled that it's not an exact explanation.
