It is probably to protect copyrighted material. If you can record the screen, then you can potentially record a movie or other content you do not have the rights to. If you need to show people how to use an iOS app, it could be possible with Swift, Apple's programming language. read more
Apple doesn't ban screen recorder apps, Apple doesn't allow any app to be able to record the screen once you press the home button, and you're at the main screen. read more
The Vidyo iOS screen recording app showed up in the App Store on Wednesday, but Apple promptly pulled it on Thursday morning, according to TechCrunch. The app being allowed in the App Store came as a surprise to begin with, since Apple bans such screen recording capabilities on iOS devices. read more