I don't disagree with you, ecosystems are both delicate and robust in cycles. The focus on parasitism is also because it is believed that there is more parasite

I don't disagree with you, ecosystems are both delicate and robust in cycles. The focus on parasitism is also because it is believed that there is more parasite life than non-parasite life. From the article: >Or, as Kevin Lafferty, a marine ecologist for the US Geological Survey puts it, “Parasitism is the most popular lifestyle on Earth.” >So popular, in fact, that many parasites are themselves prey to their own parasites. In a phenomenon called “hyperparasitism,” parasites are invaded by parasites that are invaded by still more parasites. These Russian dolls of internal flesh-eating have been observed to five levels down, which one article describes as “an endless progression of interspecies abuse”: