^ Wrong thread for that discussion bro. But I'll still bite, cause I'm a sucker for this kind of discussion.
I agree more events where one side has to defend something would actually be good for the server activity. Every time I see a bored cap AFKing outside 'Hattan I get sad because the guy obviously has nothing to do but hope that some randoms will log to gank him.
Sieges obviously help with that activity but there is very little incentive to join defenders because the battles are usually pretty one-sided. One side is organized with the goal of destruction, and the defenders - usually lawful factions have to "pretend to care".
And there's the ownership issue. The f*** you, got mine mentality. If you actually had to defend something for which existed a common sense of ownership, such as you faction's battleship or a vital trade corridor / commodity source you might actually see much more balanced numbers.