Why Apple’s A5 Is So Big, And Siri Is 4S-only — A Possible Explanation

Why Apple’s A5 Is So Big, And Siri Is 4S-only:

Integration of Audience’s EarSmart on the iPhone 4S’ A5 could explain why Apple decided to not offer Siri on older devices, and why it will likely only feature the voice-based assistant on newer devices going forward.

(Via MacStories)

Here, at least, is an explanation for why Apple doesn’t offer Siri on older iPhones. If it’s really that simple, though, why wouldn’t Apple just come out and say it? That’s taking secrecy too far.