To be fair, you could say the same thing about any material pre-prequels. Hell, you can say that about the prequels themselves - we know the Empire has to rise and the Jedi Order gets wiped out. And yes, we do know that there is eventually a happy ending, with the death of the Emperor and redemption of Anakin, but we get a similar ending in Legacy. Krayt is defeated, the good guys are victorious and become the dominant power again, the Jedi are far from destroyed. They triumphed against the Sith. It's true that the Sith are still out there, but I prefer that. The Sith are like the Daleks. They always come back, no matter what, no matter how utterly they are destroyed. I much prefer to see the eventual return of the enemy foreshadowed in the survival of at least a few members of the original, rather than every return becoming more and more contrived as to how they got restarted. It's very much a bright ending, just with lots of story-telling opportunity left. I guess it comes down to taste. I personally cared a lot for Cade's crew, specifically seeing that loyal friendship that was developed. Jariah and Deliah never had to fight the Sith, never needed to stick with Cade, but they did, a gesture that is truly touching. I did admittedly tire of Cade at times, but his refusal to fight the enemy makes his eventual heroism all the more, for lack of a better word, heroic. It means a lot more. And it's hard to deny that by the end of "War" that Cade has become a hero. To each their own.