Because it's not so much brand specific as it's device specific. Companies are still testing the waters with adding this to their differently priced lineups to see what backlash they get from each group.
If you're one of those customers who has to do this, connect it via ethernet, do the setup, then forever leave it disconnected. Never give it your wireless credentials. I personally wouldn't trust the TV to forget the credentials and not phone home and make itself the ad machine the company wants it to be