It's easy - QWERTY keyboards add bulk and complexity, and people don't buy them anyway (in appreciable amounts). Out of those that do, a large minority would buy the same phone without a keyboard if they weren't given a choice (check out the droid forums for many examples) A general N950 release would cannibalise sales of the N9, increase warranty repairs & returns, reduce the scale of production for each device and not sell very well. That's not counting the extra R&D costs, marketing, etc. It's a shame, but it just doesn't make sense.