The big thing that's missing in Cosby's argument-aside from the fact that he seems to think that the black community woke up one day and collectively decided to no longer strive or live decently or, basically, give a damn about anything- which obviously never happened- is that he somehow never seems to have noticed the thing that did more than anything else to damage the black community:

Redlining.

Redlining is the deliberate government policy, put in place for some bizarre reason in the late 1930s, to order insurance agencies and banks to cease offering their services to anyone who lived in historically Black, Latino/a/x,(and in some cases working-class white) neighborhoods. The term "redlining" came from the city maps on which federal officials drew lines around those neighborhoods.

When they drew those lines, federal officials consigned whole neighborhoods-neighborhoods that had done nothing to deserve such treatment-to slow, agonizing economic and social deaths.

It's a simple, but devastating sequence of events:

Neighborhoods where no one can get credit or insurance are neighborhoods where small businesses can't survive.

Neighborhoods where small businesses can't survive can't maintain a functioning economy and therefore there can't be jobs.

Neighborhoods where there are no jobs are places where the middle-class values cosby talks about cannot survive, where few if any people can possible have enough sense of hope and possibility to see any point in striving and self-improvement.

Redlining is what it takes to drive people to the point where they riot over poundcake.