Privacy-preserving federated login options are a good thing. Knowing that the app, which may or may not have security or data protection, has less access to my information is good. I don't necessarily like Facebook, Google, or Apple having access to my information, but if they're the only ones, it's still better than having the app developer have it. Moreover, Apple's login is presented to the user as a user-positive feature: I can obfuscate my personal information conveniently. I like that.
If an app didn't have federated login, I'd make a judgment call about whether or not I want to create an account. Maybe I would, maybe I wouldn't. But if it does have a federated login option, I'd like them to support a variety of options, including Apple.
I'm not sure Apple should mandate it in the way they do, I can appreciate that the developer feels strongarmed... in the same way that I'm sure credit card processors engage in shady strongarming behavior of retailers. But I'd still rather go to stores that take credit in addition to (or instead of) cash, and I don't find it noble that the developer is writing that being forced to do something that his users would benefit from is bad for him.
I then read the second post the author wrote about getting his app removed from the Play store for not including a link to the privacy policy and it kinda comes off the same way. I don't necessarily like Google arbitrarily removing stuff with no notice, but I do like that Google has decided that a privacy policy should be a requirement of an app, and I sort of resent the guy complaining that he shouldn't have to follow that rule, which benefits me. He characterizes this as a "bad experience for users". I don't really agree.