That info only came about recently. Until someone on reddit figured it out, we all just assumed it was OS bloat, or some other magic. That's why everyone's so upset.
I have an iPhone 6, and I don't mind the speed but the battery suddenly started to be drawn done a lot more than before (sometime last Nov/Dec IIRC). I don't use the phone for much, so it was quite noticeable when I would be down to 80% after one phone call.