There’s an old saying: if all you’ve got is a hammer, everything looks like a nail.
Willi Kampmann

Willi, let me quote your points:

And yes, that’s also Alexa’s — I notice that every day. It’s so annoying to tell Alexa something and she repeatedly doesn’t understand it.

Here you complain about the stupidity of most chatbots (or metabots as Alexa, Siri, Cortana, etc.) and I agree with you. I wrote a bunch of articles about the lack of statefull, a real conversational user experience and fake artificial intelligence in many (famous) proposals.

I’m not certain whether that’s what people want from their TV.

Good point. 
I believe, with my displeasure, that most people is satisfied with basic “pre-packed” patterns of behaviour, aka skills or functions that TVhub will supply: wheather forecasts, news, notifications, webTV/webRadio/music channels selections, drop-in, messages, audio/videocalls, quick ecommerce/convcomm, etc. (see what happens in China with WeChat).

Because that, I feel Amazon (with this Echo Show prototype) is in the way of a “mainstream” success…

BTW, that’s no more just a technological discussion but brings to social and economic considerations of our societies (someone could mention #idiocracy) …

My provocation and honest question is:

Even if we would posses the technology of a real GAI (General purpose artificial intelligence) to make chatbots able to go into an intimate dialog with users and a mutual awareness, people (see Amazon consumers) would happy to use this fantastic technology?

Your concept of a “TV hub” feels almost anachronistic to me. The trend appears to go into a different direction: the TV loses importance, and people tend to have more screens in their lives. An IoT hub sure, but I think everything else is completely unpredictable right now. In fact, Microsoft pretty much tried your concept with the Xbox One and Kinect (which I really liked), but the mainstream wasn’t interested.

Apparently you are right. 
And please do not misunderstand me: I am NOT an apologist of any centralist media of info dispatch (Television, Mainframe, SaaS, etc.). I’m for pervasive distributed computing indeed, my side. But we are talking here about Amazon, isn’t it?

The company have the power to fully reverse the nowadays trend with mobile phones, to converge consumers activities in itself. And Amazon Echo Show is a perfect symbol and prototype of this return to a television-like “centralization” (you say “stactionary”, I instead say “family-centric”).

So it’s Amazon discovering a new humanity, a new soft way in man-machine interface? Not exactly…

Amazon just want to achieve all consumers everywhere and Home & Family are a huge market (yet unexplored). That’s it.
And this “TV hub” substituting home phones, really? Who even uses home phones anymore?? In the western world, the market share of home phones is dropping fast, and in developing countries like India they are skipped altogether.

Maybe I’m wrong, but I convinced that Amazon also want to gain all Telco realms business: messaging, audio and video calls. All.

BTW, I’m from Italy and you are right, landline phones are dropping fast, but in Italy majority of families own an house phone, and any serious company own at least one landline phone (in a physical office…).

I think mobility is key. You’ve got that with videochat on mobile phones. In fact, you’ve got that with the original Echo and Echo Dot since they work across the room. But a stationary device to have to sit down in front of to chat? No way.

Mobility is just a part of the whole,

Amazon want all consumers: on mobility as at home!

The company will probably realize a pervasive computing, just to sell as much as possible of these kind of interactive TVs, just terminals to suck users in the mainframe grid.

Now Amazon Echo Show is the new breach in a partial unexplored huge market:

Home, sweet home. Family, sweet family