There are tons of TVs that are doing it right. Apple doesn't need to "show everyone how it's done". This particular example is of one manufacturer messing up one product line.
I haven't seen a single set-top box or TV with an interface that even merited being called "shitty." The space is totally barren of anyone with any UX sense.
It's unfortunately endemic to the whole industry. My "smart" TV is a Vizio.
Really I wish TV manufacturers would offer "monitors" (screens without TV tuners). If one manufacturer goes this way, people who only want a screen for e.g. their Roku might buy that one instead.
I'm not sure what you're looking for exactly, just buy a monitor. We do Smart TV app development across a variety of platforms (Smart TV's, Rokus, Xbox) and the vast majority of this development is done on off the shelf 24" Monitor's with HDMI inputs. We joke all the time that the cheapest TVs are in the monitor aisle. (This is only true to a certain size however)
I should note the LG TVs in the OP are actually great test machines too...
Perhaps consider buying a commercial display then. Not only do thye lack tuners, but if there is an ethernet port, it is most likely there for you to use to remote control the display. The only downside is that they typically cost a bit more.
The example you picked, Vizio, is the lowest-end brand on the market. Nothing wrong with cheap, for the price you pay, but the whole point is that it cuts corners and isn't as good as the name brands.
Unfortunately, this isn't free for the manufacturers, and most people are not going to want to spend the same (still less, more) on a TV with fewer features -- even if they'll never use them.
About the smartness aspect of it:
You have set top boxes like Roku which are designed well. Hell my PS3 is fairly easy to use. The previous generation of the LG smart TVs were also pretty good without having to deal with the gestures.
As for dealing with switching the inputs, many older TVs and computer monitors come with a simple enough mechanism to switch between various inputs. This particular article may be about regression in the UI.
There is nothing "new" Apple can do here. If they end up doing something it will not be not that far off from existing and very functional UIs.
If Apple does something here, I guarantee you that you will be wrong.
The big thing is the if. Apple isn't going to enter this space to create another "me, too" product. They are only going to enter the space if they can do to TV what the iPhone did to mobile phones.
A lot of people think Jobs' implied that they had figured out the TV interface. I hope so, because I'm with a large majority of others in this thread: current "smart TV" is stupid and completely lacks imagination.
Samsung's smart tv was a fantastic experience for me personally -- in fact it made me regret I hadn't bought a TV sooner. UN55F6300 was the model we had (and, after ~6 months parted ways with to go back to our ipad) and enjoyed every minute of it.
There were some caveats like the keyboard on the remote not working inside some 3rd party apps. that the TV allowed you to install.