In Apple's case, I don't think a lack of common sense is the problem. With the iPhone making the bulk to Apple's revenue, this is a textbook example of a "strategy tax" [0], and the thing about strategy taxes is they're
really hard to overcome even when you can see the issue staring you dead in the face. It takes very uncommon leadership to hobble your cash cow.
[0] http://scripting.com/davenet/2001/04/30/strategyTax.html