I was with you right up until that last line. I live in a city, though not as densely populated as NYC, and it takes physical and mental effort to ignore homeless people. I have gotten better at it over the years, but there are a handful of reasons why a person would do so that do not include, as you put it, not "caring about the rest of humanity" or not "good at empathy ". Are you describing yourself, people you know, or just carrying the party line?
I agree that there needs to be a wake up call for people who may have become numb to the issue, but imo those people needing it are not the majority of those walking down the street every day.
Homelessness is a heart wrenching and COMPLICATED issue. And the (newish) dynamics of adapting to living in city environments are complicated as well.
Were the people in the video specifically known to be oblivious or insensitive to homelessness? Or were they policy makers? If not, then sadly I think this exercise was a complete waste of time.
If we really care about homelessness, we need to target message(s) to policy makers and the voting public as a whole. Trying to guilt-trip pedestrians one at a time, when there is little that they individually can do about it, is a waste of resources.