http://autoweek.com/article/classic-ads ... dailydrive
A subject that can probably be discussed (technically) for hours.
The summary is, GM has before, did then, and has since released products prior to their really being fully baked. The divergence of the discussion surrounds what happens as a result. Basically, the reputation is tarnished, and any resulting improvement is rendered overcome by events. In a business sense, this is just the ballgame. Unless marketed as such, using customers in an R&D process won't typically yield positive results, even if the fundamental idea (and eventual implementation) was good, or at least not bad.
In another sense, GM took what was a decent reputation, one of "they'll pretty much buy anything we make" and turned it pretty sour. I happen to enjoy finding the silver linings of their engineering foibles, which I guess makes me biased. But it's undeniable that it's bad long term business to betray that trust. Witness VW. We'll see how that goes.