#2 doesn't seem to consider how much stuff there is out there. Why bother harvesting resources from a gravity-laden planet when you can almost certainly get them from asteroids or other places?

Furthermore, while we may not care about "ants", we do - at least to some degree - care about the impact on wildlife and the environment. Probably not as much as we should, but our concern has only grown over time, so I'm not sure I buy the suggestion that a super-advanced civilization would go the extreme opposite way and not care about the impact it has on "lesser" life forms.