Software Piracy

Wwhy aint they using something like a public key to encrypt the executable? If decryption is built in into CPU then it will be a lot harder to reverse engineer, because pirates wont be to see the code which gets unencrypted only inside of the CPU. Reversing modern CPU even to retrieve small the decryption key is very costly.

Have you heard of Intel SGX?

It's full of DRM and DO NOT WANT.