I haven't seen the video, but I agree that if the two people in it were paid and knew they were being filmed, THEY were not exploited.
I can see where advocates for the homeless (I'm one) would be upset, however. Such a video tends to make people think that ALL homeless people are like those two, when nothing could be further from the truth. A significant percentage of people living in homeless shelters are mothers with children, for example.
If you want a take on a very different segment of the homeless population, you can read the essay I wrote a while back about
Clarity Rose