How can pitcher plant and veenus flytrap not be an insectivorous plant ?

Pitcher plant and Venus Flytrap are said to be carnivorous plants not insectivorous plants because they do not specialize in capturing insects, they consume whatever they can. In fact they consume things like insects, spiders, crustaceans and other small soil and water-living invertebrates and protozoans, lizards, mice, rats, and other small vertebrates.