Idk, they have plenty of interesting quests specially if you use "Legion Quests Expanded" from nexus, a legion playthrough lets you be an espy and even kill a frickin president!

@1A exactly

Even going back to the early fallout games, I'd tend to do the first play-through as a "good guy" or at least civilized. My second play-through of fallout 1 and 2, I played a character without any moral baggage... stealing, working for bad guys, profit-motivated, ruthless, selfish. Both were different and interesting experiences. Led to very different ending epilogues.
That being said, I think the legion has little to offer the courier other than violence and just a desire to be "bad."
Mr. House gives the courier great wealth and every luxury, the independent ending gives the courier personal power and authority. Those are the two things that most of my selfish characters are motivated by. No one really tries to just bribe the courier into doing something horrible, at least nothing is coming to mind right now.