I wouldn't like this either. The current rate of day/night cycles is just fine and enables you to see both, and its quite frankly not that hard to keep track of the two different times. If the only difference is day vs. night, there should also be a time of twilight transition, giving you a visual queue without even having to look at the exact game time. Most of the time I have no reason to pay attention to real time anyways, and if you've got somewhere you need to be, set an alarm.

While time-restricted content may not be necessary, done right it can also add a lot of depth to whatever its used in. So that argument doesn't go very far IMO.

Finally, let's say you do sync it to a certain time zone... now what latitude do you use? The length of daylight changes much more dramatically the closer to the poles you are, and doesn't change at all on the equator. And what about the latitude of the region of the game you're in, let alone the real world? Hell, it will only even match if you live in the center of the time zone, if you're near a zone boundary the transitions would be half an hour off. I also imagine NA/EU will only get one, maybe 2, servers per region so which time zone within those regions gets picked? Does one coast or the other get screwed? It's much more complex an issue than it seems at the surface.

The only argument I can buy here is for the cycle to be lengthed to say 2 hours per day instead of 1 hour, or something similar. But as many have pointed out, 24h just isn't right for an MMO, let the single player games deal with that level of realism.