Get it right from the start?
Why not just the right display instead of 1080p display, oh why Apple why? Why not get it right from the start?
1. Apple is probably trying to cut cost. It use commonly available 1080p panel that we have seen on many competitors’ devices. Apple has to keep a certain profit margin and it is not like iPhone 6+ price differs a lot from iPhone 6. It’s only $100 more expensive. Bigger screen, bigger battery, better camera. And potentially iPhone 6+ cutting into iPad sales. Where do we cover the lost to begin with?
2. Supply of panels. If Apple has to come out with its own customized display, will iPhone 6+ be delayed?
It’s not going to be resolution-gate case instead I can say Apple pulled a smart move. A move that:
1. In the future, let’s imagine the next iPhone 7+. Apple can return to original 1242px by 2208px without much changes and clashes with app developers.
2. It fits nicely to satisfy the DPI requirement and effective device resolution. Physically 1080p, but way more than 1080p.
3. Cost wise helps the profit margin
4. Tapping on available supply helps Apple quickly produce iPhone 6+ to meet the demands.
And yes it hurts that Apple is willing to compromise.
TLDR; In the landscape of touch devices, PPI is getting higher and higher. An exercise of choosing the right scaling factor has to be carried out to get the touch devices fit into acceptable range of DPIs. At the heart of the implementation, Apple chose precise 3x scaling for its iPhone 6+ at 462ppi/154dpi 1242px by 2208px. But it is downsampled to fit its physical 1080p panel.