The terms 'herps' and 'herpetology' are used to describe a non-natural grouping that used to be thought of as natural. Herpetology is the study of an unnatural group and everyone in herpetology knows this (I hope). This is not a problem because whenever we do science that pertains to evolution we try to work with monophyletic groups only. No one is trying to come up with a phylogeny of herps and leaves out mammals and birds.
By the way some of the people who are invloved in this discussion need to look up the term 'teleology' and think about it before they try to explain why animals have certain 'adaptations'.