I don't believe his intent was to explicitly frame anyone as anything, so much as lay bare the social tapestry of modern society as experienced by both invalids and the elite. The juxtaposition and framing of scenes are important. For example in the lead up to the climax of the film, we see how the rain merely inconvenienced the elite family and literally ruined the invalids entire material existence. This is an attempt to show the audience the wide variety of experiences one particular event can have, based on where the individual is "observing it from", so to speak.
No one came out looking good, Jessica, as told by the elite mother during a phone call, was to serve a vital part of her son's birthday party, yet moments after Jessica was attacked during the birthday party, while she lay before everyone, blood still pouring out of her chest, the elite parents instantaneously abandoned her and disregarded her well being, just as the elites so often disregard the invalids of society, and instead only noticed and showed concern for their own son, who ironically was not even in any real danger of death, so not shockingly, this vast indifference towards her daughter, by the elites, caused Jessica's father to finally at last lose control of his temperament and murder the other father. He never flipped out or lost his cool with regards to the various "smell comments" or other insults, throughout the film, it wasn't until his own daughter was so callously thrown by the wayside, that finally triggered and ultimately unleashed his mounting inner resentment towards the elites, culminating in murder.
There was definitely no effort to garner sympathy towards this particular act of vengeance. I think its admirable and also necessary not to fetishize poverty and those who are poor. It is paramount not to reduce victims of systemic inequality into mere token ideals of "good" simply by virtue of their immense suffering, as suffering does not build character as so many philosophers believe, nor does it automatically make one a better person. Its important to remind ourselves, that as we and our society, strive towards justice, that not only the just deserve justice.
Its been such a common and disingenuous argument against minority right's historically and you hear still to this day, the idea that one does not deserve justice and that they are not ready for equality, because they are not yet able to follow or understand its ideals and thus unable to withstand the ultimate burden of freedom. In fact, there are no "prerequisites" for philosophic values, these prerequisites are always just impositions, rationalized as an excuse to deprive others of natural rights, given under the veneer of sincerity. There are countless variations of arguments of that nature. You see it now mostly aimed towards the poor, which un-ironically also happen to be at a disproportionate rate, minorities. If you give the poor something, this something being material subsistence, which they did not "earn", than you will stifle their ability to ever be financially independent and thus always keep them dependent upon societies continued help, or in other words, a Parasite...
Perfect analysis.