Asteroid mining and space industry is a huge reason, and it's the next logical step for humanity, especially since it means we can put dirty industry where nature and life doesn't exist.

There are absurd amounts of resources in space, a lot of which are difficult to access or rare on earth. In addition, space can give opportunities for new forms of manufacturing, from being able to control the level of gravity due to weightlessness, to being surrounded by vacuum. Two things which are either very difficult or impossible to recreate on earth.