That's because, like her creator, she thinks that trying to train pets is a waste of time as today's strip demonstrates.
Panel 1: We start off with Mike holding Farley's leash; John says "Now, Mike, you're the boss. You let Farley know his limits, see."
Panel 2: He foes on to explain that all he need do is say heel as he pulls up smartly on the leash and the dog will automatically....
Panel 3: ...drag Mike behind him as he yells "HEEL!!!" because dogs simply can't be trained.
Summary: This whole arc is based on the training of the real Farley and how it failed; given how Lynn thinks pets should be treated, it's obvious that she was the error in the system. Her sullen refusal to do what she was told pretty much guaranteed that the poor animal was doomed to be destroyed.