Because, as of today, most people do not do the work to get a war. Only the more organized and pvp orientated players push influence so that a war can get started. Lesser motivated players will not run pvp missions, as a group, on hostile territory if they keep getting killed. You have to be flagged to push influence. And, you need those organized and motivated pvp players to pull that off. And, once a war is declared, the people whom ran that influence usually get priority in it. So, you may sign up for the war. But, if you do not know the people in the company running the war, good luck getting selected. Why would anyone push influence and pay for a war if they know they cannot participate in it or win it?
PVP orientated companies are the ones whom are largely pushing territory influence. And, as such, they should get priority in participation of it. For those people whom largely do PVE content, you must become a PVP player, run influence, kill and get killed and purchase the war in order to participate in it.
War is not a sign up board. It is a team effort to win territory. So, a casual pvp’r will always be largely locked out of a war.
obviously not in this specific case.
rant over.