Some Mac APIs Available Only To Apps Sold Through Online Mac App Store

I'm looking at this as an iOS developer and not a Mac App developer, but I think this is overblown a bit.

In this case, the APIs are the iCloud related features. There are many reasons to allow only approved apps access. First, to some extent Apple are subsidizing the cost of iCloud and they want to ensure that they get their piece of any app using it. Also, it gives Apple the opportunity to make sure that an app that uses iCloud doesn't abuse it. In fact, I've had an iOS app rejected because it was putting to much data in iCloud. (Which wasn't unexpected, the customer for the app was warned it would likely happen)

I'll be worried if it applies to an API not related to a service but rather a core piece of tech.

It's not that this API is available to App Store only apps, it is that it is available only if you have a signing key from Apple. That is because these APIs make connections to Apple's server. It would make sense that Apple would, you know, not let just everyone into their server with every user's information.

So, this post is blatantly misleading, and whoever wrote it should be ashamed.