Comment by Andrex

I mean, why did we go to Mars without any intention of colonizing it? The Moon?

Exploration is what humans do. If Alpha Centauri is only 5 years away, you can bet we're sending people there no matter what. Permanent colonization only becomes a priority in an existential event, and if we eventually achieve ~1.0C travel then that implies our tech is at a level we'd be colonizing Mars and a few moons long before we think about leaving the solar system.

Even getting to 0.9C is going to be very very hard for humanity.