Great example. The iPhone 6 is the first time an iPhone camera has taken a step backwards.
Doesn't mean the camera itself is worse, but the way they've changed the software makes the end result worse in many cases. The 3rd party apps are somewhat better but even they aren't entirely free from this. I suspect some of this is built into that photo-processing part of the A8 that they spoke about.
It's a result of Apple's zero-tolence policy towards gain noise. It's absurd. Of course you want to lower the noise, but killing it across the board leads to this effect which is much, much worse.