Many people I know liked Kotor more than the movies. Also in Revan, LucasArts have an asset that can generate them a lot of profit and could be an iconic figure as big as Vader. To be fair, it is obvious that he was created as a perfect Vader and it's not a coincidence that in many polls Revan vs Vader, Revan won by a big margin (TOR forums). Also, Revan's revelation is at-least on pair with "I am your father" twist. I don't understand why LA don't adapt that story which has a perfect protagonist, a perfect twist and very good antagonists.