It's just such a well worn cliche in the EU... the good guy who has a "past" as a former bad guy drone. I guess once they brought Vader back to the "good side" that opened the floodgates! Every edgy anti-hero who was too good to get fooled by the bad guy's mind control that fooled everyone else...
Hey I liked Kyle Katarn, but back then it was still sort of interesting. Now everybody's a reformed evil-doer. Can't the bad guys have a plan that works for once?
The EU is supposed to expand things yes, but all to often it takes a good idea and totally runs it into the ground, or else just tries to undermine it. Not always but enough to make me think they're not even trying sometimes!