Buff guns used to be enabled when buffs were on ground. It became darned near impossible to take a base unless you flattened the entire thing because everyone would up in buffs and be an instant AAA ackstar.
It was so bad at times with so many buffs on the runway that everyone's frame rate was like 3 or 4.
Also, enemy fields would get de-acked and people would land buffs at the enemy field and it was a giant AAA ackstar fest there too. Imagine 15 sets of buffs (both freindly and enemy) sitting on the ground all over an airfield shooting away at each other.
It was done, and it didn't work out well. Admittedly, it was funny for a while, but it impeded game play extensively.