Let me get this out of the way first. I loved the New Jedi Order series. It may have had inconsitent quality over its run do to the number of authors involved, but at it's worst it was never bad. I felt that it was a maturing of the Star Wars story. Yes, the universe is a dangerous place for our heroes and they could die. Yes, the universe is more complicated than 'Jedi are good, everything they don't like is bad.' The younger generation grows into their roles as the next heroes while the older characters remain legends. There was room in Star Wars for bad guys who were not Sith or Bounty Hunters.
To me, therefore, Legacy of the Force was more than just an inconsistent and poorly written mess that engaged in horrible character derailment. It was a step back into the black and white picture of the pre-NJO universe. The lessons and revelations of the NJO were discarded out of hand and the retcon (not even fully confirmed) of Vergere as a Sith serves as the way out of giving an explanation for forgetting about the changes in the understanding of the force she introduced.
What is most frustrating is that the seeds for a good story that would have moved Star Wars forward were tere in the beginning, in the conflict with Correlia. The question of what the Jedi are supposed to do in a conflict where neither side is more right or wrong than the other would have been a fantastic subject to explore, as would seeing how the differing personalities led to differing views on which side to take or whether to take a side at all. Alternatively, the idea of Jacen as 'the man who doesn't exist' could have been played from an entirely different angle. Making him another demented sith lord was one of the worst moves possible, and making that portrayal the focus of the story resulted in everything that could have been good falling by the wayside halfway through.
With the deaths or derailment of so much of the post Return of the Jedi generation it is hard to see how the EU can ever recover. Fate of the Jedi is better, to be sure, but the damage to the franchise can be felt in each book, in the lack of certain characters, in the hackneyed explanation for Jacen's actions, and in the plot itself.
As far as I am concerned, The Unifying Force is the final book in the Star Wars EU. Everything since is just fanfiction, especially about the Mandalorians.