I think especially in the last three years, the race to bigger sizes and more features has been too fast. Manufacturers are cutting corners to stay in the game.
In the late '90s, if you wanted a "big" monitor, which at that point was 19" CRT (1280x960 @100Hz), you had to pay ~700€. At the start of '00s (...zerosies?), if you wanted a "big" monitor, which at that point was 22" CRT (1600x1200 @100Hz) or 17" TN (1024x768 @60Hz), you had to pay ~800€. Then there's a slight gap when I didn't pay that much attention, but at the start of '10s (...tensies?), if you wanted a "big" monitor, which at that point was 27" TN (or 24" IPS, both 1080p 60Hz), you had to pay ~500€. The more frequent discussion about different monitor flaws had already begun. Now, few years later, we're looking at 27" 144Hz 1440p IPS/VA monitors at the 500€ range, and think they are too expensive and too flawed.
In this particular case, we're looking at XB321HK, which is 32" 4k IPS for 900€ (which is practically a 600-700€ monitor, with a 200-300€ G-Sync premium, btw). You could alternatively get a basic 40" 4k VA panel for 560€, or a 43" 4k IPS (10bit) for 660€.
When we could actually get a 27" 1080p IPS/VA for 160€, as well.
It's not that the monitors have become too expensive. We just want so much more so fast, that the manufacturers will have to cram more and more features to cater the market needs, and we get blinded by what is "average", and what is cheaply made high-end. If looking at the average evolution of monitors, there's no chance that those 32-40" 4k monitors can hold the same quality control level as the older generations' 800€ range could.
If you want to compare 800€ range monitors, where you can actually (and rightfully) expect a better quality control, then I would look into something like:
NEC MultiSync EA274WMi for 750€
Eizo FlexScan EV2750W for 760€
Those are 27" 2560x1440 60Hz IPS. But you can also get a monitor with the same base features for as low as 250€ (Hannspree HQ271HPG). Should we expect the same quality control? No. You could also get a 32" 1440p 60Hz VA for 350€ (HP Pavilion 32, Acer EB321HQ). Should we expect the same quality control? Hell no.
And that's just for regular day-to-day monitors. For gaming it's a little bit trickier, as most of the 144Hz gaming monitors are indeed "corner-cutting" monitors, with manufacturers trying to cram every possible feature into a package as cheaply as possible. Which is understandable, as e-sports has risen in popularity, and everyone wants a cut.
So, when looking at the market with an objective eye, there are indeed not that many high quality gaming monitors. Then there's the G-Sync premium (/nVidia tax), which throws off the curve even more, so the 800€ G-Sync monitors would be more comparable with 600€ non-G-Sync in quality, when otherwise keeping the same features.
For a more comparable high-end gaming alternative, you would have to look at the Eizo Foris FS2735 for 930€ (27" 1440p IPS 144Hz FreeSync).
In conclusion, we just have to make a distinction between "expensive" and "a lot of money". The gaming monitors we are usually discussing here are by no means "expensive" for the features they offer, but they do cost "a lot of money". They are monitors that manufacturers try to provide for feature-hungry gamer masses, who would rather gamble on getting a good unit, than paying extra for a guaranteed quality. Don't get me wrong, I know for a fact that there are people who would be more than willing to pay 100-200€ extra to get the "real" advertised monitor without the usual flaws. And manufacturers could indeed provide models like these (maybe not for a mere 100€ price difference, though). Unfortunately, it is too niche a market that manufacturers would be interested in making them, because they know that the masses would simply skip them, if they can get the same FEATURES for less. Indeed, enthusiasts just aren't that lucrative as a market.
At some point I thought/hoped that maybe the market will correct itself, when the flaws get so bad that people start returning the units enmasse. But no, that probably won't happen. Because the gaming masses might not necessarily even acknowledge the flaws as faults, let alone care enough to send the units back.
Nevertheless, one should also take into account the internet-factor, even more-so after the rise of social media. People can share their horror stories very easily nowadays, and the news travel fast. There are indeed lower quality control standards as of late, but I also think that the "catastrophe" stories are more pronounced than what they actually are. People are more eager to tell their bad experiences, and internet provides an easy and far-reaching venue to do this.
Ps. Actually, I think I am one of those people who are creating the problem, and not voting with their wallets. In my case, I was the feature-hungry gamer, and I first set certain features as a minimum starting point (>30" but preferably ~40", 144Hz, FreeSync, non-TN). In my case the choice was simple, as there was only five choices available, and four of them were 21:9 35", and only one 16:9, the Acer XZ321Q. I opted for more vertical height, and thus the XZ321Q was the way to go. Even though I KNEW that for 500€ it couldn't possibly have the same quality control as the earlier generations, I still bought it. In the end, I got a better unit than I feared. But there is also the expected slight motion blurriness of VA panels, and it's still smaller than what I would have wanted. But because that is the only monitor that fits my requirements, there is no benefit in returning it, either. There is currently nothing to "upgrade" to, in my case. (And my next monitor will DEFINITELY be 40" or more.)
Ps2. For potential manufacturers reading this: don't think this means that you could up your price so that enthusiasts would think your monitor should have better quality control. Because if you don't actually increase the quality control as well, your units WILL be sent back even more frequently, as at that point, the price/quality is simply unacceptable.
