I swore it off a couple books into LOTF. Making a certain someone an outright villain was lazy and cheap, and the characterization of Luke and the other Jedi was too much to take. At one point Luke murders an unarmed prisoner and feels no remorse over it, he tortures his nephew instead of justly killing him, and he leads an insurrection against the government because they won't obey his orders.
LOTF as a concept sickens me as a SWEU fan, and as a historian, it makes little sense to me. So the galaxy that suffered through the Clone Wars, the Galactic Civil War, and the Yuuzhan Vong Wars wants to go through another galactic war over stupid politics? It would have made more sense if Garm Bel Iblis had a disagreement with the leaders of the Alliance and that caused the split, since he's a patriot against the Empire and one of the early rebel leaders, but they follow Thracken-Sal Solo? Really? And the Alliance war heroes go to war against the very same Alliance that they stood by against the Empire and the Vong? It makes no sense, and it just proves Palpatine was right about the galaxy and its politicians.
The ending was tarded (OMG we can't kill the Muslims Vong because they're people like us with feelings!) but it set Jacen up as Luke's potential successor and seemed to promise cool stories in the future (but we know how that turned out).
Agreed, but the decline with the SW book fandom began with NJO. A lot of them really didn't like the Vong, (even though I liked the concept of the Vong and the first half of the story). Many book fans walked away during or after NJO, and even more walked out after LOTF, since, as you said, Jacen was set up to be Luke's potential successor, but the stories that they ended up with ruined the promise of Jacen leading a new Jedi Order. And yes, you are right in how the ending made no sense. Although to me, it made no sense how a weakened New Republic and Empire who were getting their bottoms deflowered by the Vong suddenly had the spine to not only halt their advance, but to knock them back and completely defeat them. That's like what if Britain single-handedly invaded Fortress Europe and took Berlin after beating back the Nazi air raids.
If that was the case, then the Empire at the height of its power, or hell, even the Clone Wars-era Republic, would've been able to easily beat them. It destroys the threat level and coolness factor of the enemy if they are easily defeated by such pathetic forces such as the remnants of the Empire and the New Republic. The least they could have done is have a good explanation why the Vong started losing, be it the Allied forces bringing out new weapons projects, like say, mass-manufactured Dark Troopers, World Devastators, a new Galaxy Gun, or the Jedi coming up with something, like Luke and his students using Battle Meditation or Force Storms and turning the tide of entire battles in favor of the New Republic or the Imperial Remnant.
And yes, it is rather weird that they couldn't just deal with the Vong after all they did. Perhaps the Vong should've been driven to a corner of the galaxy where their forces had to live under Imperial/New Republic occupation, have the Vong be ruled by the Jeedai heretics among them, or they should have been banished from the galaxy altogether. But just letting them off the hook like that made no sense. That's like if we defeat the Nazis but we let them keep Germany unoccupied, even after finding out about all they've done. At least the Vong version of the Reconstruction after the American Civil War or a partition of Vong space a la Germany post-1945 should have been done.
You could even have some tension between the Jedi and the Empire by having the Empire force much of the Vong warrior caste into slave labor to accelerate the rebuilding efforts after the war, and the Jedi would complain about that because see slavery as immoral, but then many leaders and much of the galactic populace agree with what the Empire is doing because they suffered so much under the Vong, and there are even those who believe the Empire hasn't gone far enough. There's your plot for a new post-Vong era conflict; the Jedi would simply want to rehabilitate the Vong, the rest of the galaxy wants them enslaved or worse. That would make far more sense than the "MUH PLANETARY NATIONALISM" crap that LOTF went with.
tl;dr - the old EU had a lot of shit in it.
The key is to sift through the shit and throw it out, and treasure the stuff which was great.