I love my iPhone but...It's all about choice!
There is plenty of quality programming on worldwide FM...and it's all FREE! Considering what consumers pay for these devices and how easily this feature could be enabled, the intentional omission of FM radio is a huge letdown. Most people don't walk around with a separate FM receiver. In a major emergency (not exactly unforeseeable nowadays) FM radio is far more resilient and robust than the cellular system or WiFi.
IMO, the reason Apple cripples the capability is threefold:
1. Reception requires at least an 18" external wire antenna (EarPods would work fine) - but this would directly contradict Apple's leading the charge away from wired anything.
2. They have a vested interest selling paid streaming services in Apple Music.
3. Customers listening to free radio spend less time making purchases in the iTunes and App Stores.
In other words....There's nothing in it for them!
You actually left out one important thing.
The carriers themselves don't want FM Radio included.
Verizon phones that would normally have the function have it crippled.
The unlocked LG G6 (US997) has FM fully working including the tuning app.
The same phone, with the same hardware, does not include the app or software drivers to make it work.
Was this LG? Nope Verizon.
So before we all start blaming Apple, Samsung, LG, etc. The carriers have a lot to be accountable for because they ask that the functionality be turned off. Here again, they don't get money from you listening to FM, but they do earn money directly from TuneIn Radio and iHeart Radio because it uses data.