Sad this happened because I really liked the S4. All my HTC phones are unlocked, S-Off and the whole nine. I had this phone for only 4 days and besides it's beauty, it was a disheartening experience. I think this trumps the Optimus L9's experience of a locked bootloader. Even the Optimus G Pro's bootloader can be unlocked using an app.
I think Sammy wants to be Apple in regards to how Apple has a user experience of being locked. Also with the fake S3s/S4s/Note out there they probably do not want their software cloned.
I will say in the 4 days I had it it prompted me to start a business. I learned how to root and unlock the phone just by switching modems and running regionlockaway.