Warranty, dead pixels, having to send it back to get a good one, colour representaion
Plenty of expensive PVA/IPS screens come with very poor pre-configured colours; spending £150 more on a monitor doesn't really mean that it will be better unless you have access to calibration hardware. Look at most reviews and you'll see even expensive models often come with
horrible pre-configured settings when it comes to colour accuracy.
I really don't understand the way manufacturers do this, especially when these monitors cost a decent amount more. Even Iiyama's budget TN monitor comes pre-configured with an average E delta of 2. If Iiyama can manage this with a really cheap monitor for the masses, I find it astonishing that so many premium monitors come so badly set up. I suppose their rationalisation is that most folk don't know their gamma from their elbow, so they don't see the point. However, if a monitor was guaranteed to come out of the box with accurate colours, they could probably use it as a selling point.
The vast majority of people don't have access to a colour calibration tool, let alone know what one is. Amateurs and people who want colour good fidelity but don't have the means to achieve it would be interested in a monitor that comes pre-calibrated to some degree.
The only folk who have colour calibration tools generally don't care what the monitor's initial settings are because they can get it nicely configured later on.
I know that you can't get a monitor spot-on without driver level colour table alterations, but it'd be nice if manufacturers could
at least give it a go. When you see premium monitors shipping with e deltas > 6, it takes the proverbial ...wee.
I hope that, one day in the future, monitors and their specific panel types will be identifiable by the OS, which will then find all potential calibration profiles and ask the user to choose one. I.e. you would be almost guaranteed a good (not saying perfect) calibration regardless of monitor, revision or panel type as long as there existed a profile for it.