BASE SHIELD idea totally awesome and then totally ruined

[Akuvar]

In Reach, i don't know how many times I wished for a base shield so that I could isolate areas of the map for just one team (weapons cache, vehicles, secret passages, etc) and then Halo 4 gives it to us! Totally awesome, except, in play a person can just throw a grenade or bash the shield twice and it goes down and they gain access to the area. Why in the world would you create something great and then make it worthless? I tried setting the respawn for the shield to "never" and "1" but that doesn't help. Even if this feature were valuable, if they had created an option "shield invulnerability on/off" in the edit object, we could use it however we wanted.