And that number of people is just too small, and unfortunately a company cannot just spend huge resources (manufacturing, support, spare parts, software, etc) for a small segment. Look at Android. There’s hardly any Android phone smaller than 5” nowadays, with even budget phones going 6” or larger. And they are the one having the majority market share.
It is unfortunate, yes, but at least Apple is improving Apple Watch. I can see future Apple Watch to be my first interaction point for major tasks that the iPhone size itself won’t matter anymore. Heck, I wish apple put Apple Watch support on the iPad so I can just use a cellular iPad and an Apple Watch, skipping the iPhone altogether.