They're hurting because their super high profits and margins have attracted an amazing array of competition and left them plenty of room to get a toe in the water. The fear is they're going to go from being the absolute leader in this space in terms of volumes, margins and profits to a smaller bit player. There is a sense that history is repeating itself.
"Delving deeper into the retention and user metrics, iPhone and iPad users are 52% more loyal to their apps than Android users. A healthy 35% of Apple iOS users launched an app more than 10 times after downloading, compared to 23% of Android users."
I'm finding conflicting numbers on mobile browser share, but none of them are making the iPhone look particularly weak either.
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I see two scenarios that could theoretically actually hurt Apple (not just in a slowed growth kind of way, but by actually causing their revenue to fall): iPhone users ditch the platform for something else they like better, or another platform becomes more lucrative to develop for, causing developers to abandon the iOS App Store and leading users to abandon the iPhone over the lack of new and updated apps.
From the bits of data I can dig up, that doesn't look like a terribly immediate threat: iPhone users are still ridiculously loyal to the platform and still far more willing to spend money on apps. Some of this is old data and things change quickly, so life could be worse for Apple than I realize.
That said, the closest things I could find to reasons to worry: Android users do seem to be becoming increasingly happy with their phones, or at least the platform, and they're downloading apps at a rate approaching what Apple's App Store sees, even if it hasn't led to the same developer revenues iOS produces yet. Apple's dominance profit-wise is far from guaranteed, and Android is a legitimate threat that could eventually bring down the empire.
I'm having a hard time believing Apple's hurting at the moment though in any way besides a drop in share price. Revenue is healthy and growing. iPhone sales are healthy and growing. Profit is healthy if a bit stagnant. (Ironically enough, it's a decline in margins hurting Apple right now, not sales.) iPhone users seem to like their phones enough to buy upgrades, and to buy and use apps on them, and Apple is still winning new converts.
If this is what hurting is, Apple sure makes hurting look attractive.
Pay attention to context: the poster is responding to the grandparent's question of "How is Apple hurting exactly". Any response besides a straight denial would take the form "they're hurting because..."