Interesting post, but I find his perspective to be a destructive one. The issue is not one of human values; the issue is that, owing to anthropogenic activities, the environment is changing at accelerating rates that critical species and processes can’t survive, leading to irreversible changes. The ever increasing burden of invasive species is a part of that dangerous situation.
A single species invasion can be accommodated – systems adapt, it is the ecological history of our planet, one of perturbation and restabilization – but the enormous quantity of changes that are currently unfolding contribute to the ongoing collapses (or, to use a less judgement-laden tone, reorganizations) of entire ecosystems that we are experiencing today. Invasive species apologists like to point to examples of non-native species that don’t appear to be causing damage, and sometimes even advocate them as enhancements of biodiversity, but they lack the perspective to make that claim on sound science. Fundamental to the field of ecology is an understanding that systems are far more complex than we can conceive, and our models and explanations are only the best approximation that we can offer until new information improves upon them. Just because you cannot see the impacts of an invasive species on a few sympatric species in your size- and time-biased samples does not mean that the species is not problematic at smaller or larger scales, spatially, temporally or ecologically. To judge a non-native species as non-problematic is, in my opinion, arrogant. Our biased perspectives might be the only starting point for triaging conservation efforts, but they should not supplant the precautionary principle of conservation policy.
We will never restore pristine wilderness (that, to me, is something of a straw-man argument, since conservation never has and probably never will have the resources and cultural support to achieve that end), but I am of the opinion that we must try anything and everything at our disposal to preserve long-established (i.e. native) systems and slow ecological changes – whether they come from climate, pollution, species invasions, etc. – so that more ecosystem processes have time to adapt. The world’s ecosystems are still changing, most in ways that disadvantage humans and many many other species, but perhaps more species and processes will be survive if they have time to adapt.