Queue timers for premade BGs

Hi!
Im the guildleader of a pure PvP guild on outland.
My question regards the fact that you do not seem to be able to queue up with more then 5 people at once. The fact that we are only pvp leads to many people wanting to do pvp in guildgroups. A 5 man team get almost instant pops, however as soon as we queue up with more then that we never ever get a pop. For example we were 7 people two days ago queueing up, we waited for 40 minutes without a single pop. When 2 left the group, almost instantly we got a queue pop. That's happend more then once too. Is this a bug? Is there any point in trying to make a full 10man or more group?
In my opinion this ruins some of the fun for us who doesnt have the time or the will to pursue the PvE content.

Regards, Sajm.