You don't even have to wait for the seeds to hatch. Tank runs near them, healer heals the tank and all the seeds aggro. Tank grabs available mobs and the team clears them while seeds hatch. It does not make the dungeon longer at all. Whenever I see leveling people in the group and someone is killing the seeds, the only reasons I can think of are ignorance or malice. They are denying others free experience points.

AV is awesome. It's one of the few places where heal-over-time heals can reach their full potential, where tanks get to practice careful pulling and dps can practice their burst (seeds on last boss). It's basic stuff but a wake-up call for many.