That makes no sense at all. Before the Prethoryn Scourge we were ready to adapt, to improve, to create a utopia for all sentient beings. Why should we let them change our values? The past cannot be altered, so rather than look inward and back with a lifeless memorial or nostalgic fantasy, we must look outward and forward by creating a true utopia. Earth shall be the first of a galaxy of ideal planets!
It is only thus, by staying true to our dreams and ideals no matter the circumstances, that we may claim spiritually never to have left earth.
This...makes the opposite of sense to me. The goal is to return to Earth. Not some pretty facsimile, not some Disneyland fairy-tale version of the homeworld, but EARTH.
I know we can never return the world to exactly the way it once was; impact craters, if nothing else, will have forever altered the landscape, and countless species are undoubtedly extinct. But if we want to claim, in spirit if nothing else, that we had never left Earth, then let's return it to the way it once was. The flowing rivers AND the burning deserts. The lush jungles AND the frozen wastelands. From the open plains to the darkest caves, from the deepest oceans to the highest mountains, we must restore Earth as a Continental world in all its glory.
Ideally, I'd like to terraform Olympia back into an ice world as well. I can't even begin to imagine how many species, adapted to the frigid cold, are now either extinct or live on only in climate-controlled zoos. If we want perfectly ideal, universal climates, that's what habitats are for.