I think the business of wagons not selling in the US is part self-fulfilling prophecy, part out-dated thinking and part by design.
-companies bring in a tiny number of wagons, don't promote them, and guess what? they don't sell (Mazda 6, anyone?). If you bring in a healthy number and support them, they'll sell. The V70, Legacy and Jetta Wagon are all proof.
-auto execs and forecasters seem to be stuck in what used to sell versus what will sell, and GM seem to be among the worst at this. Missing the boat on the Cruz hatchbacks while Focus, Mazda 3 and Impreza HB's sell in droves is just one example. Yeah, the Caprice wagon didn't sell. Get over it!
-auto mfg's seem to make better margins on crossovers loaded with gadgets, so that's what they're inclined to push.
GM would have a great opportunity to bring this in and sway a lot of people who ordinarily wouldn't look at GM because they don't make anything they like--and potentially gain loyal customers as well as sales. History seems to make me think they won't do this, and those people will continue to look at auto makers more willing to given them what they want, versus what they think they want....