...the cultural materials of late-Pleistocene and aboriginal peoples suggest that such social traditions originated at least as early as the period 40,000–20,000 years B.P.
Cultural materials (amber, sea shells, stone tools) often occur hundreds of kilometers from their points of origin indicating intergroup contacts over wide areas (Klein 1989, 376–8). No such evidence of social contact occurs before the late-Pleistocene...Bottom line: if trading with outsiders is too much for you, your days are numbered.
Not so much that, I think, as it is a case of "Adapt or die."
The Neanderthals weren't willing to, or weren't capable of, altering their ways. The were becalmed in the shallows of Time, whereas the Cro-Magn. had -- by fate, luck, or design -- caught the tide and rode, and continues to ride, it into the future.