Any reason NOT to chose PvP

So, i was thinking.. is there any reason NOT to chose playing on a pvp server? I mean, WAR is ALL about the war between the order and destruction.  It would be kinda stupid to run past you enemy if you was in war with em. The Dark elfs are trying to claim their homeland back, wouldnt it just be stupid to run past 5-10 different high elfs then, when you are invading what they claims as "their country". I mean, wouldnt the High elfs try to defend their land, instead of walking by the enemy forces, being all LADIDA ? i know there is rvr zones, but cmon, its a WAR, and thats what its all about...