Oh, excuse me if I didn't get his quote correct. The gist of the matter is that the Cobalt was an awful car. Synonyms include terrible, horrible, atrocious, bad, revolting, repulsive, horrid, need I go on?
Rebadging. It's the EXACT same car with different grilles.
Platform sharing. Of course the underbody will be similar, they ride on the same platform. Moreover, the Buick has vastly more NVH engineering than the Acadia.