>> They struggle enormously at providing solid cloud services,
> So does everyone else.
That's fair, but given the size of Apple they're doing disproportionately poorly.
>> their websites suck (particularly their developer portals),
> I'm sure consumers care about developer portals.
I didn't say consumers care. Consumers care about design, which is what Apple focus on, that's my point!
>> they can't write a functional USB stack,
> Never had any problems with it.
Plug in a USB 3 hub. Any USB 3 hub... seriously.
>> macOS has more bugs than ever,
> How did you quantify this?
As mentioned, Apple have a complete lack of transparency that makes this difficult to quantify. However, articles like https://eclecticlight.co/2016/09/28/known-bugs-in-macos-sier... give some incite. I've been using OS X/macOS for years, and at least in my personal experience it's been mostly downhill since Snow Leopard. Finder is particularly buggy, although Apple Mail also crashes at least once a week. Waking from sleep seems to wreak havoc on all sorts of things, why does my mouse and keyboard start playing up?
>> even iOS' stability seems to be going downhill.
> How did you quantify this?
As above. Just personal experience. I genuinely do not use iOS much, I do admit that. I use it purely for development, a lot of which recently is just web development. However, Safari seems to have an uncanny ability to crash iOS entirely! Allocate a lot of large WebGL textures and watch the system burn.
EDIT: To clarify the "downhill" statement, large WebGL texture allocations on iOS 8 do not cause a system crash, just the expected Safari tab crash. On iOS 9+ you'll be sent to the white boot screen at least 50% of the time, and things will get hot (on the same iPhone hardware).