As in Wolfenstein: Enemy Territory, where most servers have disabled Panzerfausts. And some servers even have voice commands that say: "We need a panzern00b!"
I don't one hit kill games unless its team SWAT (which is crap on Halo 3, it was awesome on Halo 2).
I don't want to play a game that my 4 year old sister has a good chance at killing me.
Halo 3 has a lot of skill involved with the right items you can take down an over shield guy charging you with a shotgun without taking any damage.
Although Bungie has screwed up a lot of stuff with updates. And it gets annoying when people always go after rockets and shoot you, blow you up then tell you how "leet" they are.
PS:
80% of the time I mute the players I play with/against.