Because pashtus it’s going on a p’sul of lineage, being mirrored to him.. Like the story with the one with ten sons, nine mamzerim, the negative traits inherent inherited by rote of his ignoble beginnings. Same as why the infamous ben-nidah (yoshke II) went off the way he did.
I don’t think it really applies to anything else, e.g. if someone calls others ganav, does it mean his being is “filled” with geneivus?
And besides, the quote is almost always wrong.