Business decisions could be any number of reasons.
- Apple's market share would increase by Zero if they added an FM antenna.
- The R&D cost to make an FM receiver/antenna combo which would work as expected in this particular device far outweighs the projected increase in sales.
- The user experience may not be the best for the end customer and cause more expenditures in support, repairs and warranty claims than the inclusion would justify.
Does that help? Or do we now wish to argue the arguments? Please, explain to me this.... If it was easy to include in the existing iPhone design, cost very little to include it, did not interfere with any other equipment, and the end user experience was flawless...why WOULDN"T they have included it? because they didn't wanna? Because they don't care about the customers? Seriously....just think about it. Would it be nice to have? Sure. Even I would use it on a regular basis. But it's not. Do I need it? No. If having FM radio on a smart phone is a requirement I would look to a different manufacturer.
Why are other manufacturers disabling it on their devices now? Because they don't care either? Because it works great? I know...I know..."But it DOES work great on MY <other smartphone>." Then keep using whatever phone that fulfills your requirements. It's a very simple consumer based decision.
And I said nothing about the frequency range they use being a hinderence. I said interference. Plugging in a new ethernet cable into an existing hub can make a stand-alone, tabletop FM radio's signal go out of wack 10 feet away.