While I'll defer to Hitech and company regarding how things work, I will pass on my limited opinion on the subject.
Numbers appear way down from the "glory days"
In my mind we need more players. To that end we need to get them in to the arena. A newbie doesn't start out worrying about defending HQ. they want a chance to get in the air, find bad guys, fire thier guns and maybe kill someone.
The down HQ makes that hard. Why stick around if you can't find a fight? Throw in those of us who no longer have the hours to give to the game we once had, and the desire to log in for a quick fight or two dies fast.
So shrink the maps, encourage fights, suck in some new blood and maybe return to the days where a big map worked cause it was filled with players. At that point folks might even think it worthwhile to defend HQ
Driving folks away from the game seems counter productive to me. Even the Wizz types would eventually get bored talking to themselves on an HQ run in an empty arena