Yes, the high-ranking officers, the ones doing all the planning, probably thought mainly of the strategic value, and I'm sure propoganda and wanting to extend Allied influence were also high on the list. That's not particularly pessimistic, unfortunately.
But Phillip Spooner represents the individuals -- the "regular" soldiers and sailors and what they were thinking and feeling. My father, grandfather, and great-uncle all fought for their countries (the U.S. and Canada), and at one time or another, they all thought deeply about the higher ideals that had led them to serve. If you'd asked any of them a similar question, they would all have answered much the same way Mr. Spooner did. He's speaking for a lot of people, even if not necessarily the ones who were in power at the time.