That's actually not completely true. The complaints have gotten SE to reduce the time between position updates from .5 to .3 seconds going from beta to launch, and from .3 to .1 seconds (for end-game dungeons) in the most recent patch.
They are not likely to actually change the netcode itself though. Which is why I've started to suggest if people are still having enough trouble, they should play a different game. That doesn't mean that I think the game is fine as is. I think that if they can't make it less clunky, and don't eventually fix the netcode and/or fight design, then people will just quit out of frustration. Kinda like a portion of what happened with 1.0.
The problem isn't even having to move in advance really, the problem is that if you experience a latency spike, if their servers are bogged down, if you get packet loss, you can still get hit.. regardless of how much you learn an encounter, or how much in advance you move. You position just isn't hitting the servers before the servers decided you take damage. When you combine the frustration of being hit when you saw you were clearly out, plus the players in game yelling at you (this mainly happens in duty finder or pugs) for getting hit and calling you names.. well it really doesn't make for a good gameplay experience. I've had several friends who quit due to it, and then came out to see if it was better in 2.1 before canceling subs again.
Getting hit when you were clearly out of an AOE before the cast bar ended should never happen. Not even .1% of the time. Seeing a heal go off for more than I got hit for, but still getting killed by the hit that came right after should not happen. Those are not things that SE purposefully programmed into their game. They are side effects of a netcode that was built around the infrastructure Japan has for internet. People complaining about them have very valid complaints, and SE obviously realizes this to some extent as they have tried to bandage the problem twice now.. in addition to highlighting that as one of the things that was going to be fixed from 1.0 to 2.0, even though it wasn't.
I definitely don't think people should stop complaining. The moment they do is the moment SE figures everything is hunky dory as is, and stops attempting to do anything to address the problem, even little band-aids.