Hi BirdieMachine,
Umm.. I think you may have totally missed the concept of 'invasive' species. All species (over generations) adapt (to within the limits of their genetic diversity) to their (local) environment, and compete with other species for resources. In general, this kind of competition produces a relative balance.. i.e. there are many local species, each of which are kept in check by other local species (i.e. no one species takes over). People often think about this kind of competition in terms of predator/prey relationships, but it's also important to note that many plant species actually engage in biological 'warfare' with each other, which further keeps their populations in check.
This particular tree is not a problem in China (where it originated).. it's not 'invasive' there. The 'invasive' problem happens when (typically through human interaction/interference) we take a species that was being adequately kept in check in its local environment, and place it in a totally new environment. Suddenly, the species finds no opposition to its methods of acquiring resources, and none of its predators around either. So it is able to reproduce unchecked, rapidly taking resources from other local species. The end result: a mono-culture.
Also, rattlesnakes are 'good' for keeping rodent populations in check, which eat crops and potentially even spread diseases.
Please, do a bit more reading on the function of biodiversity. You may be surprised to learn that there really is no such thing as a species that does 'no good'. It's more a question of *where* it does good, and that 'good' might not be here.