I think so.

How high the priority should be is a debate worth having, but space has many ways to wipe out a planet. Having two planets, having a permanent space station, could go a long way to increasing survivability.

Not only that, building in a vacuum, building in zero G, even building things under great pressure, all can allow us to build new materials with brand new properties.

Also, being able to sustain a small group of people somewhere completely contained an inhospitable can be utilized on earth to feed people at home, or recycle water at home.