That leads us to the next question: How does a designer know if he has a good idea until he actually gets the position of lead game designer? The previous lead game designer also believed he had a good idea. Not only him, but the majority of the previous team ignored the community back in beta testing that the game was not ready whatsoever because they thought they had a, "good idea," for us all. What I put in bold suggests is to create this game yet again without listening to the feedback of the community; just like the beta phase.
One solution to this question would be to staff someone knowledgeable about recreation psychology :P You know, someone who can analyze what game elements are appealing to players, the things that make a game successful, and make recommendations based on that understanding of player psychology.
There's actually a fairly simple set of principles underlying good game design, but SE is still taking a trial and error approach to the problem. Well no surprise, sometimes their trials are errors.
You do know they can do all that without taking the servers down, right? Taking the servers down would be such a bad PR move that even if they were able to turn it into the perfect MMO they wouldn't be able come back.
Actually, taking the servers down is probably the best thing they could do. Obviously their existing playerbase doesn't think so, but honestly, people who are still playing the game will probably pick it right back up if they shut down the servers and reopen them later. At the rate they're going, they're probably only going to lose players from their existing playerbase, and they have almost no chance of getting any kind of player influx from nonplayers at this point.
Sometimes when a product is really substandard, the best thing for a company to do is say, "Yeah, our product sucks, but we're going to give you something completely different." e.g., Domino's Pizza, CocaCola Classic, Hardee's-- these were very successful marketing moves. Making little fixes here and there just doesn't attract players. It's why unveiling is such a common marketing tactic that you probably don't even think about it. A total relaunch will pique interest and make people curious about the game. A substantial portion of the MMO consumer population doesn't even want to play an MMO if they can't start at launch, or at least be assured that they'll be in a large wave of players. Psychologically, the only way most people will give this game another chance is if it does go caterpillar-cocoon-butterfly, disappears for a while, and emerges as something attractive.
As a caveat to this, if they revamp the battle system substantially and it's successful (and I have doubts about their ability to do this, but we'll see), and have a successful PS3 release, this could be preferable to a rebranding effort.