Angela's Ashes by Frank McCourt, for example, is about people in a very sad situation, and yet it left me cold. I was furious at the father's fecklessness at drinking away any money he got instead of spending it on feeding and clothing his children, appalled at the pious self-righteousness of the Church, and irritated by the spinelessness of the mother.
You need four elements for people to feel moved.
1. A sense of the struggle.
If everything falls into your characters' laps, tiddley pom, without them having to make any effort for it, then I'm afraid most readers will switch off fast. A character who struggles and is then rewarded, however, we engage with. The bigger the struggle, the bigger the problems, the more we engage, and the more we feel moved when they finally achieve their goals. (BTW big, in this context, means something that matters to the character big time. It doesn't necessarily mean 'big' by any other standards.)
2. The darkest moment
The struggle will be highlighted if it looks as if the character is going to lose whatever it is they are fighting for. I'm not a fan of the Hero's Journey formula when it comes to being a useful tool for actually writing a novel, but it does remind us of important features such as the darkest hour, when the character hits rock bottom. Seeing them struggle out from the pit gives us readers hope that we too will be able to get out of our own darkest moments. That's why happy endings often have us crying away.
3. Character identification
Characters need to be like the readers in some ways. They need their good and bad points. If they live in places that are far from the reader's experience (the past, the future, another planet...) then their humanity mustn't be forgotten (even if they're actually aliens).
4. Specific characteristics
Certain things are guaranteed tear jerkers....
Triumph over disaster
Examples for me include A Tale of Two Cities, The Incredible Journey, Children on the Oregon Trail, I Am David, Lord of the Rings among many others. Films are too numerous to mention, but perhaps a less obvious one is An Officer and A Gentleman, in the bit when he gives up his chance of winning the top prize (self sacrifice) to enable his class mate to succeed (loyalty). And of course the end scene - endurance, love conquers all, triumph over disaster and virtue rewarded.
And the film that inspired me to write this blog, about the rescue of the Bonita by the RNLI 30 years ago. Astounding bravery, endurance, self-sacrifice and triumph over disaster - please watch.