I agree, but unfortunately we don't really have any control over what types of games LucasArts chooses to make.
This forum is really about feedback for the LucasForums site, not for LA or their affiliate companies.
But who knows, maybe somebody will see your idea and agree..
PS: On the contrary, Mara Jade is probably one of the most over-exposed EU characters there is (other than Boba Fett). Mysteries of the Sith and Masters of Teras Kesai though were the only games where you could play as them though, true. We've yet to see a game where you could officially play as Jan in single player (without cheats).