1. How Apple has gone out of their way to prevent allowing other people from touching their devices, including influencing legislation. (It wouldn't be nearly as much of a problem if they weren't trying to get guns pointed at anyone who wanted to fix their device themselves, but the act of lobbying to make the law bend to fit your desires is bad for just about everyone.)
2. How the iPad has (nearly) succeeded at ruining the best parts of hobbies he likes, like comics.
3. Apple design principles have moved from "Sane, intuitive," to making software targeting the stereotype of "My mother's a dumb old lady; she'd never understand this!"
4. They've made a joke out of non-vendor-locked software distribution.
5. People coming to their defense have disavowed basic market principles in doing so.
I don't even mind Apple's "walled garden," but Doctorow makes sound points, and I think the article is a fantastic read, especially when paired with the article it's referencing.
I have two Linux laptops that I can do anything I want on. Fit for hacking and having fun with.
I also value my Apple closed system devices: Apple Watch + AirPods, iPhone 11 pro camera (it makes phone calls also), MacBook, and a small iPad Pro. The Apple devices sort of fade into the background for reading books, listening to music and audiobooks, and writing.
I don’t see what is wrong having open devices and also locked down devices, for different use cases.
EDIT: also, I don’t install very many apps on iOS devices and when possible use web apps. More of my software development is also now done on leased VPS. Usually, I want my local devices to be secure and convenient.