There is a hardware-based secret which emulators cannot obtain or fake. That breaks the attestation chain. At the heart of it, there is some stuff that only you

There is a hardware-based secret which emulators cannot obtain or fake. That breaks the attestation chain. At the heart of it, there is some stuff that only your processor can do and not you the user even though you may have full control over the operating system. The OS is in SGX's threat model.