Last time I checked, editing a Word doc is not the same thing as playing a video game. The whole point of my comment was to point out how inefficient it is to use your living room TV as an office monitor. Even you admit this by explaining how people have a separate monitor available so as to not cause this conflict. If the entirety of your argument is that people should hook their only PC up to their main TV, then I'm going to point out that that isn't a solution most people can use.
Yeah editing the word doc is probably more important than playing that game if it's work related. But still I can't see it as a huge inconvenience, since people talk and know each other. There's a TV show coming that my girlfiend watches, I'm probably aware of it. So I don't schedule my working on that time. Like I don't need to play a console right at the same time. With services like Netflix and HBO you can watch whenever you please.
But sure I get your point. If I'm gaming and also working using the TV, it's going to be reserved more than if just used for gaming. But this is only an issue if you make it an issue, just like with console hooked up on the living room. It can cause arguments to some couples, when Bold & Beautiful is on TV but the other one needs to raid in Destiny with their friends. If communication and respecting others wishes and needs isn't an option, then get a second tv or a monitor for the PC/console.
There was a time when consoles were seen as kids toys and their place wasn't in the living room. It changed. There was a time when PC:s were seen as tools for basement dwelling nerds, it has changed too.