I remember reading a few years back that the extinction of a species is worse than we think because it likely also leads to the extinction of exclusive parasite

I remember reading a few years back that the extinction of a species is worse than we think because it likely also leads to the extinction of exclusive parasite species. For example, if the California condor goes extinct then (maybe) that would also lead to the extinction of some louse species that exclusively parasitizes condors. The author seemed to think it obvious that this would be a bad thing, that the extinction of any species must be a bad thing, but I can't imagine why anyone would think that way. I want to save the condors, but I think the world is better off without the condor mites.