That is different to executables (which run directly on a CPU). Most data files are little more than scripts, that are interpreted by a host program. But you're not right on how programs load data files data is not always a program.

But then I think it's too broad to ban all executable code since it covers emulation too. That executed code could be further sandboxed to prevent viruses or malware. I understand why Apple rejects executable code - it could allow app stores within an app for example unless prevented by further guidelines (not saying that's necessarily a bad thing, but thats's likely their angle). Isn't programs as data and data as programs the basic principle of computing? For example, PDF files are themselves computer programs which instruct and iPad how to render a PDF visually. In reality, executing code in an emulator is what programs do. I think Apple's guideline rejecting executing code is needs to be eliminated - an emulator is an emulator.