I don't think you get it, it wasn't big mary sue epic moments that made Revan so great, it was the mask, the mystery and the magnificence, we used to have a seriously wonderuous character in Revan, but the novel threw all of that out the window and made him some has-been with no mystery left at all, the game made it even worse.
I think they took a giant **** on HK,T3,Meetra and Revan too but the only difference is Revan is the only one that can be saved because He didn't FOR SURE die on the foundry he just got DEFEATED so his character can be saved if they did something epic like my idea. They cant save the other 3 because they KILLED them off, there's nothing that can be done. I understand what your saying about leaving characters in the past but Bioware DIDNT leave them in the past they brought them back.
You can't save characters who have been robbed of their uniqueness and what made them so special, especially by just slapping random powers all over them, personality>power.
Starkiller/Galen Marek was a 'force wrecking ball' as LucasArts put it, but that didn't make him a good character by any stretch of the imagination.