While it was dumb of the developer to try and do it behind Apple's back, and they should have known they would get caught...
The logic behind Apple's rule that volume buttons cannot be used to control anything other than volume is that it may confuse users. Surely based on that, the fact that users had to go out of their way to enable the feature (more so than even changing settings within the application), the feature is only accessible to users who won't get confused.
Of course, once they discovered it, Apple did have to take the action they did (or risk opening themselves up to all developers taking the same risk), but they should consider allowing an exception to the rule for developers who make it hard enough to enable that kind of feature, while also providing users with valid warnings, documentation and an option to disable it again that is far easier than it was to enable it.
The logic behind Apple's rule that volume buttons cannot be used to control anything other than volume is that it may confuse users. Surely based on that, the fact that users had to go out of their way to enable the feature (more so than even changing settings within the application), the feature is only accessible to users who won't get confused.
Of course, once they discovered it, Apple did have to take the action they did (or risk opening themselves up to all developers taking the same risk), but they should consider allowing an exception to the rule for developers who make it hard enough to enable that kind of feature, while also providing users with valid warnings, documentation and an option to disable it again that is far easier than it was to enable it.