IMO the argument is a red-herring. Exploration and settlement of other planets doesn't preclude any action to improve conditions here on Earth. If anything, the technologies and knowledge we gain from the effort would only help us to better understand and ameliorate problems here. There seems to be some environmental guilt here, and a worry that we will ruin some other pristine place, -that "we don't deserve it" argument. I'm not sure what can be said about that. In who's eyes don't we deserve 'it'? I don't understand. Exploration and wonder is a good part of who we are. We learn about ourselves when we encounter new knowledge. We get new context and mature. Previous conflicts diminish and lose relevance as we expand our worldview. I also see this exploration as an avenue to a new era of enlightenment. If we chose not to, we stagnate.