Because that how Leaf ninjas think....Only about them self and believe what ever actions they do is deem right for they are always right.
Sand ninja at tigers? Kill them for tigers belong to leaf
Sand ninja at wolfs? Kill them this is leafs
Sand ninja not shareing caya mobs? Kill them and call them scum for not sharing map
Leaf nothing but a blood thirsty village always looking for more war. This truce just a political stunt to try to mask whats really happening and to make it seem like eveyone all nice and all but really, their raids back to back and people still stuck in in the mind set of war.
Its a pitty really to watch this.