It All Boils Down to Encryption

When a program is compiled, the resulting binary is effectivly encrypted. With no source, it cannot be reconstructed. This is the application-level version of using encryption against its users.

A vendor, or any other party, has power over their users with full-spectrum control when combining;

  1. Vendor-controlled network encryption - one cannot see what an application is passing through one's NIC, since you do not control the keys.
  2. Vendor-controlled content encryption - conventional DRM.
  3. Vendor-controlled storage encryption - ex: see Apple and locking user data to hardware decryption.
  4. Vendor-controlled firmware encryption - UEFI "secure" boot, Intel ME, AMD PSP, cryptographically signed whitelisted hardware (laptop NICs, etc) etc.
  5. Vendor-controlled application/operating system encryption - textbook definition proprietary software, also necessary to facilitate the enforcement of items 1. through 4.

Every computer is a castle, and he who holds the keys is it's reigning king.