They're also cheaper because they're subsidized. I did the same thing with a FireTV but understood the extra crap they want to boot and use is part of why they're so cheap, they're hoping for information to sell or puchases they can monetize.
We just bought a vizio to replace one that broke. Once you skip the setup process, all you need to do is remove the solder from the 'home' button on the remote or whatever it is and you'll never see their pop up crap again.
I get why people like this, though. It takes all of your accounts and puts them in one place. Honestly, if I could run Plex and my own media through it, it would be tempting to just block it from dialing out and get rid of my Nvidia shield.
The frustrating thing is the lack of options. If you buy a $300 TV or a $3000 TV it will still come loaded with bloat/ad/spyware built in.
The most insane thing which I wouldn't believe if I hadn't experienced it myself, but Samsung will periodically just install random apps and games on your phone. You delete them, then a month later, new apps show up. It's one of the most aggressive anti-consumer thing I've seen and it's coming from such a large player.