* Lack of Payment: Thorin and his company had promised to share the treasure found in the Lonely Mountain with the people of Lake-town who had aided them in their quest. However, Thorin became obsessed with reclaiming the treasure and refused to share any of it, despite the desperate need of the people of Lake-town.
* Ignoring their Needs: The people of Lake-town were struggling with a harsh winter and had lost their livelihood due to the destruction caused by Smaug. They were counting on Thorin's promise of sharing the treasure to help rebuild their lives, but Thorin ignored their pleas.
* Arrogance and Pride: Thorin's pride and obsession with the treasure made him appear arrogant and uncaring towards the people of Lake-town. He saw himself as the rightful owner of the treasure and refused to acknowledge the sacrifices made by others, including the people of Lake-town.
* Breaking the Promise: The most significant reason for the anger was the broken promise. Thorin had promised to share the treasure and then backtracked, causing distrust and resentment among the people of Lake-town.
These actions led to a conflict between Thorin and the people of Lake-town, culminating in a battle known as the Battle of Five Armies. While the anger towards Thorin was justified, it's also important to remember that the situation was complex, and Thorin was facing his own internal struggles and a sense of responsibility to his people.