It's an artifact of how they've mashed two game designs together. The world exploration is Bethesda, but the companions are modeled after Bioware. Specifically, the ship is clearly inspired by the Normandy with the visual aesthetic of the Serenity.

In Mass Effect, the system works fairly well because there is no free roaming. You do a mission, that ticks an "advance plotlines" flag", and by the time you return people have new stuff to say to you. In Outer Worlds there is no easy way to tell when you've been away for a while to advance the personal stories, so they just set it to be whenever you return to the ship.

If you're on and off the ship like many people are, then the stories get told very quickly and then sit around doing nothing until you hit a major story flag (like unlocking Byzantium) to allow accessing the next set of companion quests.

This shows itself in other ways as well - your companions can have scenes with each other when you return to the ship. But since they don't know where in the story you'll be, they just play them at random and even let them repeat.