It's all bytes but untrusted user data is stored in memory pages which are not marked executable.
The CPU physically will not run instructions which are in areas of memory which are not marked as executable. This is a foundational principal of computing security.
> In computer security, executable-space protection marks memory regions as non-executable, such that an attempt to execute machine code in these regions will cause an exception. It relies on hardware features such as the NX bit (no-execute bit), or on software emulation when hardware support is unavailable. Software emulation often introduces a performance cost, or overhead (extra processing time or resources), while hardware-based NX bit implementations have no measurable performance impact.
Wow, you're halfway there. Yes, when user data gets loaded into an executable code page - which are reserved for command data - it is a bug.
That is why LLMs - which intentionally mix user data and command data into the same space - ARE BROKEN BY DESIGN. Do you get it now? It is a bug, and it is a bug which is fundamental to the design of LLMs. There is no way to build one that does not do this.
Are you somehow under the impression that storage devices and LLMs fill the same purpose? That's a major misunderstanding. Here's a good starting point if you're struggling with the difference between a computation device and a storage device: https://en.wikipedia.org/wiki/Computer