I think being more specific by saying close to nature or not close to nature does more suit the idea. Saying uncivilized/civilized is more general, and while they do cover the patterns a lot of people portray, it's not completely accurate since people are on more of a gradient scale. Living in civilization does tend to make people weaker, but not inherently so. Knowing how to live off of the land is crucial for survival, were any sort of catastrophic event to happen. Plus, as you have mentioned, living in civilization doesn't inherently make someone that civilized either, if they're power-hungry and care little about their impact on other life.