Yes, one shouldn't pass judgement on homeless people, but the music analogy doesn't hold.
I presume that, whether you listen to country or rap, there is some degree of choice in your actions. So many homeless people end up on the streets because of mental illness or domestic violence -- things that are absolutely out of their control.
So instead, at least for me, it is difficult to see and accept homelessness as an alternative lifestyle. It requires a different level of empathy.
It's like people who listen to rap passing judgment on country music or vice versa. These represent different lifestyles and approaches to life. None is wrong - brought up in one circumstance, you would sing the one and in another the other.