remember, matt damon's character held on til he would be RESCUED off the strange planet.....he didn't try to build a home....he just survived as best he could til he could eject.
just because we FIND ourselves on a strange planet or a strange place, doesn't mean we are destined to STAY there forever.
by the way, for anyone who saw the movie of The Martian, i beg you to listen to the audiobook.........get the REAL story.