I understand both views.
If the pilots had survived it would be pretty obvious that he would sue. He almost died because of their negligence. But since they died then the question becomes does that make the lawsuit redundant or meaningless? Obviously putting it in simplified terms, "he is suing the dead people's families", looks pretty crude but it could have been like a blanket lawsuit that held all parties down the line accountable (airport, airplane maker, the pilots, etc) and the pilot's death may not have been reason enough legally for them to make a special exclusion of accountability? I don't know how it works but I'm trying to think past the simplified idea that he wanted dead people's family's will money.
With the pilots dead, there are likely children without parents now, husbands without wives or vice versa.
These people left behind get the estate as some token of their loss to help lessen that blow. If DJ AM was trying to take that away from them, he was suing the families in essence. I don't see whats so hard to understand about that. It could impact college educations for children, the ability to keep a house for these families, everything.
He wasn't suing some invisible, magical pile of money somewhere.
Championships for MY teams in my lifetime:
Cincinnati Reds - 75, 76, 90
Chicago Blackhawks - 10, 13, 15
University of Kentucky - 78, 96, 98, 12
Chicago Bulls - 91, 92, 93, 96, 97, 98