People reference the essay, and in so doing they are referencing the whole essay, including the nasty parts.
People doing this need to be aware of that; I suspect many are not.
Being cited doesn't make anything true, so I'm not sure what that has to do with it being correct or not.
There does exist scholarly work disputing Hardin's conjecture. For example, the work of Elinor Ostrom of Indiana University.
"Ostrom received the 2009 Nobel Prize in Economic Sciences for her groundbreaking research demonstrating that ordinary people are capable of creating rules and institutions that allow for the sustainable and equitable management of shared resources. She shared the prize with Oliver Williamson, a University of California economist."