Hey gang, long time lurker first time poster. Listen, I understand that in these kinds of shows, character behavior is wholly subservient to the needs of plot, symbolism, and theme. Characters do the things they do because the writers need a thing to happen that advances the plot. Or they want to represent something without calling it out specifically in dialog.
So for example, characters smoke and chew because the writer wants to subliminally draw attention to oral ingestion/expulsion, and to signal the cavalier disregard these characters have to their health and well-being. As a writer, once you establish this symbolism you get to create cool associations, you can then have a scene where Morrow, in full analytical mode, flicks his cigar down the hole made by alien acid blood. The cigar, a notional representation of Morrow's deep and pensive thought; the hole, a kind of notional throat.
All this being said, though, wouldn't it be neat if there were diagetic reasons for the characters' behavior as well? What if some part of cryogenic sleep (either the process itself, or the drugs that make it possible) actually makes people dumber, less logical, and less connected to their emotional state? Maybe these people leave for their long voyage perfectly competent, intelligent managers, engineers, and scientists, but by the time their corpsicles are thawed out years later, some part of their brains just never thaw out or something.