Either one of those things can be very detrimental to programming outside of work. Not saying this is all romantic relationships, but it's very common for a partner to have an expectation that you spend a significant portion of your outside-work time with them. And single people who have a social life also can let socializing monopolize their outside-work time (though of course there are also people who may only talk to friends once or twice a week).
For many (including myself) it's really hard to balance relationships with solitary hobbies.
