1. The limitations of the oppressed vs. oppressor view of the world, which is very popular at the moment. It takes a comfort with cognitive dissonance to accept that some haves aren’t necessarily oppressors, but it’s easy to assume that they are. See also: the scorn heaped upon small time landlords.
2. Accepting that some people will take advantage of a given situation, even homelessness, for their own gain is a very disconcerting thought if you tend towards empathy for homeless people. I struggle with accepting this myself, even though I can see it happening in front of me.
3. The bifurcation of all political ideology into Republican vs. Democrat, and the suspicion of crypto-Republicanism that is now levied at ideas outside the acceptable Overton window.
4. Bitter jealousy towards people who have managed to secure property in a desirable area that others feel locked out of due to rising costs. I used to feel this quite intensely myself.
Or, you know, wake up to find shit on their driveways, smashed windows on their cars, needles thrown on the street, etc.
Rationally you can think "that's just the mental illness or addiction causing someone to behave that way". But over time, even if you rationalize the behavior it wears down on your empathy.