Why Apple will make smart glasses

It's easy to dismiss the speculation that Apple is working on smart glasses.
It's hard to picture Apple selling smart glasses. But it's also hard to picture them not doing it.
If smart glasses become a popular and mainstream consumer electronics category, Apple will almost be required to enter the market as a fiduciary responsibility to Apple shareholders.
Consider the plight of poor Apple. Smartphone margins are shrinking. The tablet market is flabby. Smartwatches aren't panning out as a mains