> Space exploration can be done cheaper and safer with machines, so there is no need to risk human lives in space
> Space exploration and space tourism is wasting Earth’s finite resources
Both of these arguments miss the point that the Earth is not going be here forever for us. If we are to thrive as a species, spreading out humans to multiple planets and moons is the only viable way. Any investment that goes into exploration and survival of the species is worth more than anything else.
> Colonising other celestial bodies for resources and human habitation removes the incentive for being sustainable on Earth
Even if we do colonize foreign celestial bodies, they are unlikely to be anything like the beautifully complex life ecosystem that is our Earth. And as the most intelligent species on the planet (although this can be argued), it is our responsibility to preserve it and help it thrive moving ahead.