If they're going to buy a regular iPhone for $100 more anyway, and the likelihood they buy a small Android instead is near zero (what small Android?), then yes, I absolutely would say to cut it and simplify the engineering, manufacturing, and checkout process.
If you start serving every 4% of needs in each product category, watch the portfolio balloon to catastrophic proportions. The very principle of the thing is anti-Apple; they would quickly become Samsung, complete with Samsung level naming schemes and weird decision making. Next thing you know, we'll have the Apple Vacuum Cleaner, the Apple Door Lock, the Apple Ice Cream Scoop, the Apple Exterior Camera, and so on.
This slippery slope argument doesn't click for me. They obviously perceive the value of segmenting the market by device size. I'm just asking for the smaller size to be actually small.