This article explains it all. I guess GM would rather sell an $75k Sierra than a $110k Blackwing. Yeah, real strategic. Once you lose a customer they rarely come back:
For the first time since 1931, General Motors Co. isn’t the top-selling automaker in the U.S. The Detroit-based manufacturer lost its crown to Japanese rival Toyota Motor Corp., which boosted sales 10% last year despite a 28% decline in the fourth quarter. With 2.3 million units sold in the U.S...
www.autofinancenews.net
“That forced GM to be strategic about where it dedicated supplies. In a dismal quarter, sales of the Chevy Tahoe and Suburban, GMC Yukon and Cadillac Escalade large sport utility vehicles all were up. Those are the most profitable vehicles the company sells.”