Texask, it can be eco-cleansing - similar to ethnic cleansing. For some people, if you aren't native you are snuffed.
We have managed to get some changes here. Weedy environments are sometimes all that there is now for some species. The native habitat is gone or severely reduced. Habitat rehabilitation now has to take this into consideration. Attempting natural can be wrong.
Some populations of introduced animal and plant species now are critical important populations because of the decline of those species in their countries of origins.
Trees (such as the eucalypts you mention) can now be registered as of cultural or heritage significance and subject to Vegetation Protection Orders.
The following will never change, however: it is vitally important to conserve native vegetation.
