Biblical quotes in the article are from the New Revised Standard Version. The author of Genesis thought so. Perhaps the animal world suggested a relatively idyllic world where there were no ethical decisions to be made.
Animals simply eat, sleep, reproduce and die.
There is something enviable about not having to decide about social issues, where to send your kids to school, which church to join. Greed, shame and murder play minimal roles in the social lives of animals. Maybe it would be paradise. But conscious, ethical decision-making is part of what it means to be human. The teller of Eve and Adam's story deftly wove the tale to help us understand why humans are like we are.