Because
Sergeant
1st off thanks for the comments, really appreciate getting some feedback from TW and it's great to understand your thought processes on some of these issues.I also adviced giving leadership skill passive xp bonus effect as you said (something like training at Warband). Something like each leadership skill to give +0.05 xp to each troop in your party (example : if you have 100 leadership skill each your troop in your party will get 5 xp daily). It is rejected for now. I think same with you about this issue. It can be good if a skill is used to give passive xp and effects of leadership skill (party morale bonus and garrison size bonus) are currently weak.
Also the idea of leadership granting a passive XP bonus seems like a great way of handling levelling. I would love to see that and the enhanced training at Castles suggestion (and I my opinion only castles to make them more distinct, valuable and reflect their military nature) in the game.
Thanks again for taking the time to discuss this with us.