Earlier quoted context omitted.
They were absolutely terrible people. They weren't so poor that they had to trigger an old lady's dangerous allergy just to get the mother a job.
The point of the film was that poverty forces the poor into ruthless conflict with each other as they battle for the scraps of the rich. It’s pretty blatant. As was the indifference of the rich to the struggles of the poor and their own inhumanity toward them.
Likewise, when the main family meets the hidden family - are they generous? They have much from fleecing the rich family, and the hidden family has, and asks, for very little. Nope, the main family is cruel to the hidden family and by rejecting them they initiate the final conflict.
Other poor people aren't as mean. The original staff at the house are diligent workers. The original driver offers to go above and beyond to drive the sister home. The hidden family are dedicated servants. The first tutor tries to help his friend.