My original blog, GM should kill the Corvette, was about automotive technology. The blog has generated a heavy reader response, much of defending the Corvette and its pushrod technology.

I still think the Corvette uses highly-developed but archaic technology. However, the reasons that GM should kill the Corvette have to do with marketing, not with technology.

One of the things contributing to GM's troubles is that its divisions, which had been separate car companies, have lost their brand identity. The GM car you owned, Chevrolet, Pontiac, Oldsmobile, Buick or Cadillac, once made a statement about you that everyone from eight to 80, male or female, understood. You wore that identity like a suit of clothes. That's gone.

Chevrolet's became nearly as big and heavy as Cadillacs: same size engines, same feature sets.

Smaller Chevrolets were badge-engineered to sell as Oldsmobiles, Pontiacs, Buicks or Cadillacs, cheapening those brands.

Executives decided that it would be more economical to make one V-8 for several different divisions. A Pontiac might actually have a Chevrolet engine. In the minds of the decision makers, however, the Chevrolet engine was just as good as a Pontiac engine would have been. Who would care?

I once told a GM manager that the Cadillac Cimarron was a terrible car that did not come close to a BMW by any measure. His response: "Our customers don't know that. They'll buy it because it's a Cadillac." That kind of thinking ruins brands.