Erroneous argument. We can all agree the majority of people with a home desktop are running a 1080p screen, and of that majority, most of those screens are TN junk piles. We could also go to Steam and see that most people are running 1080p via their hardware survey as well.
Then you could take a look on Steam at what class of video card the majority of people are running as well and remind yourself the majority doesn't even know or care about the latest graphics tech or about gsync/freesync/whatever sync. Something that will make them have to get rid of their currently functional 1080p screen and buy another one, that also has an additional $200 premium for something they don't even know about or understand ? Unless and until their monitor dies most won't even consider buying a new one.
This is a niche technology targeting a niche. The problem on tech forums is the assumption that everyone who games knows about the latest and greatest and is running a R9 290X / 780ti on a top-tier Intel platform. Here on these forums you might be preaching to the choir, but the majority isn't here or cares to be. It's just not the case, those users are the minority. Until something of this sort comes rolled into every monitor as standard with no premium attached its penetration will remain amongst enthusiast PC users and gamers.
This is why you see reviewers and forum goer's opinion's of gsync often decrying the lack of announced or available IPS/IGZO screens supporting it, because they're enthusiasts and represent the niche that are even aware or interested in this technology as yet. The same niche that often understands the superiority and high quality of IPS and similar panel technologies over TN. What model of monitor are you running, dude ? Same one I am right ? Why ?
Pointing out 1080p as the most common resolution on Steam or most commonly sold screen size on Amazon does nothing to support an argument that 1080p TN makes the most sense for something like gsync. You're talking about the majority of desktop users, in the case of Amazon, many of those sales probably are not even for a gaming desktop...
I should add that the TN vs IPS argument was not the focal point. It's that gsync has been reviewed as ideal in its use between 30-60fps and is where I'm interested in using. I don't see 1080p as a resolution where you have to worry about being between 30-60fps. If your plan is to spend $500 on your gsync monitor and $200-$300 on your GPU, why spend $500 for gsync to make 30-60fps more fluid when you can spend $300 for the monitor and $400-$500 on the GPU and crush 1080p. It just doesn't make sense for such a low resolution to invest that additional $200 for gsync into what is otherwise a low-end TN monitor.
4K is where it will be put to best effect and I agree the 1440p Asus screen with it is a good fit as well, just not for me, because $800 for a TN monitor is lunacy in my book... But resolution-wise it makes sense.