Perhaps you should consider the fact that the ownership of GM has something to say about how the company is run instead of solely fingering those evil, big-cigar CEOs.
Not sure where the ownership currently stands, but the last I checked, GM is owned by:
United States Department of the Treasury (61%)
United Auto Workers Union Voluntary Employee Beneficiary Association (17.5%)
Canada Development Investment Corporation (7.9%)
Government of Ontario (3.8%)
Bond holders of Motors Liquidation Company (9.8%)
If these numbers are still accurate, now who's fault is it?