Improved attack and defend.

I have noticed that the attack and defend games are a little one sided. This is a problem to me because it just is not all that fun to be a defender. My major complaint is that there is simply no objective. I understand they are meant to be short games. But a simple time limit would make it so much more fun. I'm not asking to change any of the major rules involved simply to implement a 30 minute time limit. This helps both sides, the attackers and defenders. One example of this is the fact it will cause the attackers to be more aggressive. They will still have infinite re-spawns so it works out there. Defenders as well will now have to be more aggressive because if they survive the 30 minute limit then they win the game. I am only asking this because it has gotten stale knowing that as a defender you will eventually die and cannot win. So tell me what you think. Is this a good, bad, or useless idea?