Seeing as we had most of these maps in the"old days" it is amazing we had 600 players everynight.
I still have always thought the bases were too spread out. You can have a small map but still have bases that are too far, which make it time consuming just to get to a fight. Once the fights slowed down, these distances helped stomp out the fights. If you notice, most of the big great furballs are at the areas with the closest base distance. Long base distances and high mountains also create an atmosphere where faster planes are necessary, higher alt fighting takes place, and hoards are much more prevelant.
Also, there have been some ground game changes, like strat placement, AAA guns, puff ack, re-supply, ect. That also didn't bode well with fighters. I know splitting the MA also hurt it too, but that's a while ago.
You have to consider the attention spans of people today. The quick fight type of people that have switched to a faster game.
There should be some adjustments to base distance and am attaempt to relieve the lower #s with maps that work better to concentrate action. This will bring more players to the game, and once the #s get higher, you can bring back the bigger maps.