She is literally a diligent servant. Her job is to be a servant and she is attentive, hard working, cares about her job and the family and the house. I don't see how accurately describing her as a diligent servant shows any of my biases.
I don't think the film is the good poor versus the evil poor. I think the film is something like a rich person's horror story - the poor hold you in contempt, they're lying to you, they're parasitic off of you, and they're a danger to you and your children. Even worse, they're in your home!
Your interpretation of the film seems explicitly rejected be the film itself as I explained above.
What do you think the rich family would have done to her if they knew what she was actually doing?
What exposes your biases is that you reduce her to the superficial appearance that she puts on for the rich in order to survive. This is not only viewing her through the perspective of the wealthy in the film, but counter to what the movie itself tells you she is forced to do and become, outside this limited perspective. It’s embracing an ignorance of the entirety of her characterization that the film intentionally elaborates.
And this is what Bong Joo Ho himself said about his movie:
“I tried to express a sentiment specific to Korean culture, [but] all the responses from different audiences were pretty much the same. Essentially, we all live in the same country, called Capitalism.”
The film is a depiction of life under Capitalism and all the related tensions, violence, and inequality that comes along with it. At a certain point, refusing to acknowledge this is just being willfully obtuse.
I think if the rich family knew what the hidden family was doing they would have fired her and called the police. I think that's a totally normal and understandable reaction, but it's not the most moral reaction, which would be to help the hidden family. I think this cuts against your argument because the richest people aren't extremely moral, whereas they would be if point was that morality follows wealth. Consider the party scene where the rich father cares more for his fainted son than the stabbed poor daughter.
I think your attempt to perceive and expose my biases is unsound. I called her a diligent servant because she is, and to contrast her with the poor family. The diligent servant works hard, does her job, and earns even the extra she takes for her husband. The poor family don't really know how to do their jobs, consider the father's inattention while driving or the daughter's made up therapy, and they perform their jobs haphazardly.
The diligent servant is doing what she's doing because otherwise loan sharks will kill her husband. The poor family is doing what they're doing to make more money. The point is that the original housekeeper is behaving morally and picking the best of bad options. The poor family is behaving immorally by lying, getting people fired, poisoning the housekeeper, and stealing. Both are poor and only the main family is immoral, which again rebuts your interpretation.
I don't think the film is the good poor versus the evil poor. I think the film is something like a rich person's horror story - the poor hold you in contempt, they're lying to you, they're parasitic off of you, and they're a danger to you and your children. Even worse, they're in your home!
Your interpretation of the film seems explicitly rejected be the film itself as I explained above.