Hmm, from the TNG crew, Picard had "flings" but never settled down, he was too much of an explorer. Not unrealistic.
Riker and Troi used to be lovers but Riker dumped her for his career and probably scared of a relationship.
Worf wants to marry Kheylar, but she thinks that old-fashioned. He raises their son after she dies.
Pulaski, we have no idea but its not beyond reason that she was married at some point.
Geordi is a wet blanket and Data is a robot.
Beverly is a widow with a son and eventually married (and divorced) Picard.
So from a main cast of 7, only three are real loners. Really small sample size.
Riker and Troi used to be lovers but Riker dumped her for his career and probably scared of a relationship.
Worf wants to marry Kheylar, but she thinks that old-fashioned. He raises their son after she dies.
Pulaski, we have no idea but its not beyond reason that she was married at some point.
Geordi is a wet blanket and Data is a robot.
Beverly is a widow with a son and eventually married (and divorced) Picard.
So from a main cast of 7, only three are real loners. Really small sample size.