I understand the problem of spam in notifications, but my question is, what's wrong with deleting an app that spams you, or not installing it in the first place if you don't trust their use of push notifications?
Why don't we err in favor of the user instead of the developer? It's bad enough that they cannot get apps from anywhere but the App Store, give them a break.
The problem is not with spammy applications, but with others that you don't need notifications at all. I don't know, new Google's Hangouts, I don't want to receive notifications, but I don't want to delete it, because I may use it sometime.
Also, you're thinking as a developer. As a developer that cares on the user, so you probably are thinking that your app will have internal notification settings, about frequency and which to notify, but in the real world it's not a standard, sadly.