Am I my brothers keeper? Culturally, we've just bought into the notion that I'm not your therapist, so as to absolve myself of the responsibility of fixing broken people. But if I don't do it, who will? so I take care of myself first, so that I'm sable to take care of others, but when I encounter broken people, I still try to fix them (as if people are devices like microwave ovens that need fixing) , because we all have to live in a society and hurt people hurt people, so don't over extend yourself, but also do the work that's staring you in the face.
Therein lies the crux of the issue. Everyone agrees that this person needs help, but also agrees that they shouldn't feel obligated to provide it.
And so they continue on, blissfully unaware of the chafing they cause. Life goes on, and their contribution remains minimal.