We should be given experience for killing enemy players or bosses... And the exp points should depend on the level of bosses and enemy players....
For example, of a level 14 sentinel player kills a level 15 mc.... Then he should be given more exp than a Lev 18 sentinel who kills the same mc...
Same goes for bosses if a lev 14 player kills a Lev 15 bos.... He should be given more exp than a Lev 18 player who kills the same boss...