Of course I'm not assuming pc gamers never use large televisions. I don't think I should I have to qualify that.
It's just a small base. The number of people who have a PC that can drive 4K and near 120fps is even smaller. The number of people willing to swap a TV for this even smaller.
Check the nVidia image on the sign up page - they have a horribly undersized rendition of it sitting on a desk. If the argument is, "At worst it's bad marketing" then, ok, if I see nVidia marketing about how great it is to replace your huge TV with it and how perfect it is for living room gaming, I'll concede. But I bet I won't see any of that.
Just seems like an expensive product that very few people will want, and not in the normal, "It's for the high end market" way, but in the "this is a dumb product" way.
I do understand somewhat where you're coming from. However, I think you're underselling the value of this TV's feature suite, by assuming that the only people who can take advantage of it are those who own rigs capable of driving 4K and 120fps in all games.
gsync, for example, is a feature which enables frames to display as soon as they're rendered, as opposed to in line with a strict refresh rate. This feature, formerly exclusive to computer monitors, eliminates vertical tearing entirely and makes it so that uneven framerates and framerates that aren't locked appear smooth. And that enables PC gamers several interesting choices. My computer isn't top of the line, and so I often find myself compromising settings in favor of a locked and smooth framerate on my standard monitors and televisions, when I'm playing high-spec games. That's because my monitor, and TVs in general, operate at fixed refresh rates, and so frames display at fixed intervals. gsync screens display frames as soon as they're rendered, so they appear far smoother in motion. This enables the user more freedom to enhance settings and resolution, without having to consider fluctiations (which would thereby have them settling at lower settings in favor of a consistent framerate across the whole game).
And so, if I owned, say, a 4K 120hz gsync monitor, I would have more freedom across the board. I could boost my settings in a high-spec PC game like GTA V, and run it at 4K with very high settings, without having to compromise for the sake of smoothness and input response time. I could eliminate the judder in my BoTW resultant from my computer running the game at just short of 60fps. In addition, I could play many of the games I own and play that aren't as high-spec - like Divinity OS 2, Civilization, Prey, Tabletop Simulator, Gang Beasts, Brawlout, Skyrim, ArmA, Geometry Wars 3, Far Cry 4, you name it - at or near 4K and 120fps (or 110fps, or 102 fps, or an uneven 90fps, thanks to gsync). It's a very popular feature in contemporary monitors for that reason - and until now, it's been exclusive to computer monitors.
I, like many other PC gamers, do enjoy playing games on my TV - whether they be particular single player games, or local multiplayer games. However, TVs generally aren't built for gaming specifically like gaming monitors are. And so PC gamers are typically left to compromise when the choice is made. Those compromises can include noticeable input latency, the absence of gsync, extraneous features which negatively impact image quality and response time, the absence of true 120hz (keeping users at locked 60 or 30fps max) and so forth. This TV seems to bear a competent enough feature-set to compete with other contemporary HDR TVs, and enables PC gamers more choice with far fewer compromises. On this TV, I'll be able to play Breath of the Wild at 4K and 58fps, without experiencing the constant and noticeable judder that comes with playing at that framerate on my current monitor and television. I'll be able to play Prey from my couch at 2660p, at framerates much higher and smoother than on my other screens. I'll be able to play Street Fighter with my friends with no input latency, regardless of whether the framerate is locked or unlocked. I'll be able to play high-spec games at ultra settings and high resolutions at framerates short of 60fps without noticing. On a TV. It's pretty compelling for me, and my computer isn't even top of the line - I've got a 970 and a 4790k.
I'm not saying that this TV will be a profound success, or anything. I'm just saying that personally, I think that its features make it unique enough among TVs of its kind that it will bear compelling value to a number of potential owners. Just as similar computer monitors bear compelling value to a number of owners compared to standard monitors, for the same reasons, but with the benefit that this is the only large TV on the market that can hang with those monitors on a lot of levels. Time will tell, though. I already want one to replace my living room TV, lol