Steve Jobs has a saying that A players hire A players; B players hire C players; and C players hire D players. It doesn't take long to get to Z players. This trickle-down effect causes bozo explosions in companies.
General Motors, like the other two geezers of the Old Three, is a vast retirement home with a small money-losing auto subsidiary.
Harman had great brands, but the processes were falling apart.
Even the greatest companies encounter problems or otherwise fall out of favour.
Borders had lousy management and made bad corporate decisions, so its fate is less like a terrible accident than a slow-motion slide into a ditch, but it's hard to be happy about a bookseller's demise.
All of us can expect to live longer than any organization that we would work for. That continues apace. Human longevity is increasing; corporate longevity is decreasing.