I think I know the answer, and the answer is protecting SUV sales.
Nearly every major manufacturer offers at least one AWD car now, but GM doesn't. Granted, they have the Vibe(rator) and the Saabaru, but neither are truly GM cars.
In certain areas of the country I'm sure it is no big deal, but in some areas it really affects GM's sales. Rocky Mountains, upper New England, etc.
They had the 6000STE for about five minutes. Other than that ?????
Subaru has a big niche these days. I know GM has a minor financial interest in Subaru, but that can't possibly be preventing them from competing, can it?