The thing I'd add is that Apple often achieves what it does by doing less. People assume that because Apple makes great things that they can make a lot of different great things. But that's where a lot of other companies falter: they make too many different things to really make a few great things.
Small phones are also difficult. Memory, processors, and batteries don't shrink. For an iPhone mini, they're going to be shipping essentially the same chips taking up the same amount of space. That space is going to have to come at the expense of things like the battery and cooling. It's a lot easier to engineer something with looser tolerances. If you have a giant phone, it's easy to have extra room to keep the phone cool and stuff in a battery.
It also probably meant limiting some choices for the rest of the iPhone lineup. Apple wants to be able to re-use components and to some extent it's going to mean that Apple either has to make choices that work for both a 6.1" and 5.4" form factor or do separate things.
There is some demand for an iPhone mini. I love the iPhone mini. I also see the challenge for Apple.
I think there's also a reason why we haven't seen a successful Android mini phone. It's hard to make a mini phone and the sales numbers are comparatively small.
But maybe we'll see an iPhone mini in a few years time. If Apple can create an integrated CPU/modem/WiFi/Bluetooth chip, that could end up saving a decent amount of space while also reducing power requirements. Maybe we'll be able to go SIM-less around the world and that could save space.
At the same time, it's hard to make the same number of people make another, more challenging form factor and it's hard to scale out with more people too. Plus, do you put your best engineers on the hardest project (the mini) when it's only 3% of sales? Or do you hire new, less experienced, possibly lower skilled people for that and hope you don't put out a product that isn't good?
It's a tough challenge for a tiny amount of sales which, ultimately, aren't going to decide to leave Apple for Android where they also can't get a small phone.
If small phones are difficult, why are phones getting larger as battery and semiconductor tech continues to improve?
Advances in tech should allow phones to be smaller than ever for the same capabilities, or more capabilities for the same size than ever before.
The battery may be smaller, but the power draw of the GPU and screen will also be smaller.
> they make too many different things to really make a few great things
While true of a company like Samsung I don't think this explains the lack of a small iPhone. Apple is only going for simple relative to someone like Samsung. They now have FIVE current models, spanning what is effectively two screen sizes (but actually four, which is worse, because now you're spreading yourself across FOUR form factors minimum.)
So even Apple isn't playing by the "too many different things" rule. In reality they could accomplish all this with two models: a big one and a small one. Add in a "mini" size and now you have three models, plus much better variety.
I won't quibble about what is best for Apple's bottom line though; I assume they know better than me. But I will quibble about neglecting what people are asking for while giving them things they aren't asking for.
> Small phones are also difficult.
No, they aren't. It used to be that big phones were difficult. Then screens got cheaper, and now they choose BIG every. single. time. They don't choose big because it's easy, they choose it because it sells better.