Put it this way, Omni's and pro's like them are skilled enough, why give them more of an advantage by rewarding their obscene amounts of kills with over powered rewards.
Now, I'm not saying i am completely against kill streak acknowledgement. It would be nice if every 5 kills [i.e. 5,10,15,20,etc.] a message pops up in the chat box saying something like "Player57843 has a X kill streak!" or something less corny. The idea of getting items like air strikes and stuff are kind of... stupid. The reason being, Legions maps are not like those of Call Of Duty. Our maps are much bigger and therefore air strikes would be rendered useless unless they targeted the WHOLE field, you know? Plus it could be useless if a map has large areas of the map underground or in buildings of sorts. and i have to agree with mabeline, kill streaks should just go die.