Not for the sake of our health, though it's often presented that way, but because it's an escape from the human anthill. It's an escape from our own competition, and our own dramas. And that's why ween joy looking at glaciers and oceans, and contemplating the Earth from outside its perimeters, etc. We like to feel in contact with something that is non-human, and that is so deeply important to us.
A scientist in his laboratory is not a mere technician: he is also a child confronting natural phenomena that impress him as though they were fairy tales.