Why is it so haunting?

1) because it's a song about someone who was voted off one particular show, the show being the romantic life of someone she cares about

2) because Adele is a fat chick crying about it in song, and 

3) because it's a record of a voice destroyed by a parasitic industry that doesn't care a bit about the vocal health or the long-term success of its "host".

It's not a fabulous voice at all; it's a voice damaged beyond repair, that has bled itself out twice in the last year because no one in the industry gives a $hit about Adele.  She sings like she's 50, not 23.  Another one bites the dust...