Personally, I like expeditions.
It would be nice to see some greater reward added to them, though one must remember that BB are doing all they can to ensure that expeditions are non-compulsory.
At level 30 you can get a 120 troop marshal and yet, since you have reached maxed pvp experience, there is little reason to use him...
I doubt it would harm the game if BB allowed all expeditions to continue to award star coins as well as pvp experience, whether the player was level one or thirty. If someone wanted 5 more star coins to buy a gem pack, they could do expedition rather than buff quest or Arabian Nights.