[xigma]

No, this is a permissions problem. Reading and writing to an application directory does not cause any issues until some code in that directory starts running with privileges it shouldn't have.

It should not be possible for an application that happens to install other applications to bypass the user for specific permissions. The user must be asked explicitly.

This has nothing to do with being able to "sideload" apps or not. Sideloading apps is actually possible on iOS, it's just such an effort (getting a developer account) that it's rarely done in practice.