Very good point.
My light side character goes to Korriban second because that's generally when Carth's quest to get Dustil out of there kicks in on Tatoine.
My dark side character goes to Korriban second because he wants to see the place, and doesn't want to seem too eager to go the place. Carth's quest is a convenient excuse to go there second.
I've tried the Korriban last route once with a dark side character, and the extra dialogue was rather meh. They don't believe you, anyways, plus my character doesn't need to talk about being Revan. He's more focused on getting the job done and getting the Star Forge back.