Do you really just turn your back on a family member who is making so little sense as Jahn? Don't you at least try?
You can try up to a point. My father is a hoarder and very disorganized. (My mother is in a nursing home.) He's been that way all of his life and it under treatment for GAD. Thankfully, the house doesn't come close to the state of horror of the houses on TV. His problem isn't that he constantly buys things, he just will not part with anything. He has old stuff from his childhood, as well as old stuff that belonged to his parents.
My siblings and I have tried for years to help him clean up and throw stuff away and he refuses. If we just take charge and start filling trash bags, he gets upset. We've even tried to make a fun game out of it, like, "What'll we find in this bag?"
Finally, we just threw up our hands. It's his problem. So, I don't think that the family members don't care, per se, they are probably just tired and frustrated with banging their heads against the wall.
The idea of removing the hoarder from the house while it's being cleaned up is a good one, but I just think that when they come back home, they'll start all over again.