I really don't get all this smart TV hate. They are genuinely useful. In my home we have a FreeNas server(soon to be ESXI) with movies on it.
You know that one smart TV manufacturer, LG, was caught reading the file names of the files on connected storage and did send it to LG? They did that on top of the "usual" tracking of user behavior. And while there was a menu item to turn off the tracking of user behavior, that menu item didn't turn off the snooping of your media content.
One caught, likely more to find. Mind you, that was all on top of the "usual" user tracking all smart TVs do.
If you add the fact to it that smart TV manufacturers are adding cameras an microphones to TVs - for skype video chat, ha, ha, ha - you start to get an idea what is wrong with them. Edit: Samsung's and Sony's implementation are so unsecure that they are already hacked, and people seeing the mess asked themselves if someone can really be that incompetent or if the implementations were deliberately insecure <insert your favorite conspiracy theory here>.
Manufacturers who you can't trust, incompetent engineers who don't know how to spell the word security, and all sorts of shady figures interested in getting the data, a device typically always powered and placed in a central room or private areas. Yes, the disadvantages outweigh the advantages.