"I don't care what happens to these people."
A phrase coined by Dorothy Jones Heydt in a science-fiction based Usenet group in 1991 to describe an Audience Reaction to a work of fiction where the characters are either so universally bland and unengaging or so unlikable and unsympathetic that the reader simply loses interest in their fate and, by extension, the work as a whole. This can happen with or without the presence of more objective shortcomings, but the most interesting examples tend to be those where this is a critic's main complaint, single-handedly dragging an otherwise well-made story down to where it's unengaging.
Note that "not caring about what happens to" a character is not the same as "not liking" them — some character archetypes, such as the Unsympathetic Comedy Protagonist, Hate Sink, or just a really good villain, work because they are conduits for Laser-Guided Karma. In other words, even if you hate the character, you still care about what happens to them because you want to see them get their comeuppance. After all, the opposite of love is not hate, but apathy, and this is about what happens when that apathy has set in.
Many Horror/monster/Disaster Movies try to avoid this by Developing Doomed Characters, only to make the audience care even less about the characters because they aren't getting the slaughter they came there to see, and wondering why they're spending the first quarter-to-third of the movie watching personal drama they don't give a flip about.
Also often stated with added emphasis as "I don't care what happens to these people".
See also Too Bleak, Stopped Caring, where an excessively dark setting causes audiences to stop caring even if they care about the characters as there's seemingly no chance of them getting a desirable ending. Likewise, see Opening a Can of Clones for when viewers stop caring what happens in a story because they can no longer be certain that any major plot development won't just be undone later.