So what you mean is 5 on 5, or 10 on 10, or other small numbers rather than having to engage the huge, skillless zergs that inevitably rampage blindly through the BGs on occassion. You can do that in large settings, it's just harder. Heck, Mids and Hibs could regularly school gangs of Albs double their size (not zerg-size, but more than a group.) Those fights are fun
but sometimes a good huge fight is fun too. Specialized BGs would be neat to add in after the main ones. Capture both sides of the tunnels, or something, and then kick out the support beams and laugh maniacally as the Alliance are squished under tons of rock...
Personally I think they should slap up some ghetto-ass version of the BGs and Honor system immediately if they're going to keep on doing only internal for lordy knows how much longer...