Ultimately there's a ton of pent-up demand for an Apple display, combined with the fact that there's a ton of variation in monitor tech out there and there's not really a magic bullet or even "jack of all trades" option right now. Apple's ProMotion displays are close (I think once you're past 120Hz outside of gaming the vast majority of people care much more about better color display or HDR) but ProMotion to the caliber of their small displays hasn't even made it to the expensive XDR, so expecting it in a sub-$2K monitor was always unrealistic.The main criticisms seem to be around price and lack of HDR which I think are fair enough. You can get HDR on much cheaper panels, but they're often just HD rather than 4K. You only have to look at these forums over the last x number of years to see that as screens get larger, Mac users really want nice crisp displays with high PPI which give you a "retina-like" experience.
These also have speakers, webcam and mic built-in which are selling points for some, not to mention they are design to work with Macs so shouldn't have any resolution issues/strangeness or wake-from-sleep issues.
The question is, are those things worth the price premium over other screens? That's down for each user to decide and isn't an eventuality they can cover in every review.
The other thing is that lots of reviews mention how old the panel is. Which is true, but it does still look great for those who don't need an HDR screen.
I can see both sides of this discussion and the webcam bug around the quality and centre stage doesn't help the case for these.
If you're fine with a 27" 4K display, then there's plenty of cheaper options that have most of the same features or can certainly get you to 80% of them for much less than 80% of the price. But as usual with Apple, you pay a premium for niceness.
The other bitter thing here is in some ways this is really the monitor Apple could have shipped years ago instead of having people deal with the LG 5K display that was only ever okay.