More space: great if lots of pieces are on the board (obviously), sometimes problematic in endgames if weaknesses were caused by creating such space.
So to answer your question, creating space in the opening is important to help get your pieces active. However you always need to bear in mind longer-term weaknesses, as pawns can't move backwards.
I guess the way to view it is that the pieces themselves have no intrinsic value, it's the squares they control that is important.
Is there a strong, logical argument for why we should strive to focus on space in the opening?
My theory so far is that if we are careful not to develop holes in our space, and we end up with more space than our opponent before center pawns begin being traded off, then once those center pawns are traded off the person who had more space has more maneuverability now that the center is open, thus they have more options and, statistically, a better option by that virture. Do you think this is a fair argument?