I think AM General was surprised that the Hummer could be sold as a civilian passenger vehicle. It is such a piggy car - an embarrassing testament to the Bush years of the USA's slathering over-indulgence. It was the equivelant of driving your kids to soccer in a military tank. Why? It made absolutely no sense at all other than complete vanity.
I don't know that the end of the Hummer is as surprising as the fact that it enjoyed any success in the consumer marketplace to begin with.