I agree, it would be nice too if there were a push/defend mechanic to it which would increase the match time naturally.
Eg. At so many points (or all three points held for a certain amount of time) the attackers would: break a gate, break defenses and push the defenders back into another section where it would continue. Defenders would push the attackers back out of their castle or courtyard back into the forest. Endless matches could be prevented by again having a point cap/sudden death mode.