Well, if I interpreted this comment right, if you remove THEM from the ending, it takes away from not only the heartbreak that is the ending, but the probability that it even happens in the first place. The whole point is that Marco was being forced, even if it was for a greater good. He would've been happy not giving a damn about earth if it meant staying with Amicus. And moving THEM removes the whole payoff of the Cato incident, and the explanation for the entire story happening in the first place.