As such the Psalm is a poetic description of the natural circle of life that includes both life and death as normal facets of creation.
Quite true CF, my take is that it's necessary for the life cycle / ecosystem to be self sustaining. The carcasses feed the bottom feeders and so on creating top soil all along the way through wastes. Think about it how else could it all hold together. Adam's sin does not have anything to do with some animals being meat eating killing machines, it's how they were designed and they seem to manage quite well with out us interfering. Of course I just pulled this out of my uneducated butt, but is my simple tradesman's slant.