Something we don't talk about in this debate is phone abuse. These things aren't indestructible.
If my brother and I buy the same Honda at the same time from the same dealer and I put 3,000 miles a year on mine and he puts 30,000 miles a year on his, they aren't going to perform the same way as they age.
I'm an important senior executive, so my iPhone is used primarily for emails, texts, browsing, and phone calls. On the weekends, add in still camera and videos I shoot of the family.
Meanwhile, my son is on his phone day and night, he uses it more like a TV for watching streaming movies, he's constantly gaming on it, he's getting non-stop Snapchat and Instragram notifications, he's Facetiming, he's always running the battery down to 2% and running it up to 25% before letting it go down to 2% again, not to mention 5 days a week when it lives in an equipment bag in a freezing cold ice hockey arena for 3 hours during practice followed by a 1 hour sweaty trip home on a steamy sweaty bus back to town.
Point is, who the hell knows how these people are treating (abusing) their iPhone's. I can tell you from what I read here and the way the posts are written, it sounds more like my 17 year old son writing these hate posts, not a purposeful executive like me. I could completely understand my son's iPhone having battery problems or OS problems because he's not treating it like a respectful computer, he's treating it like a lawn mower.