Reartalkin demonstrates to us just how easy it would have been for Nokia to solve the N-Gage value equation, instead of making a major strategic error by forcing people to talk out of the side of the phone.
The interesting bit is that the financial cost would have been absolutely minimal - and the earliest review I can remember, well before the official release, pointed this out.
Why didn't Nokia correct it? Because they couldn't even see that this was a mistake. They probably thought it was a minor cost of radical innovation - in fact, that's the textbook definition of radical innovation: massive positive value shift on salient dimensions, small negative value shift on nonsalient ones. And, in all fairness, Nokia had shifted consumer preferences before this, so maybe they weren't that far off the mark.