They put it in the game to combat the campers that have been ruining the game. It's almost impossible to finish a match before the timer runs out which is stupid. With you talking about people seeing you behind curtains and in impossible places leads me to believe you are one of many campers that should NOT be heard.
I dont like target finder, but everybody cries about it saying it is a noob thing, and what about the laser attachment for SMG? An attachment that allows you to kill people without even aiming!
Anyway I think that to balance the TF, it should be a extra atachment to be added to the RD, ACOG or Reflex. Taking two slots, one for the sight and one for the TF:
The only class gun that should be capable if the attachment us the LMG as it is actually a plausible attachment for it. SMGs definately not. But Treyarch decided that all guns need all attachments or you will upset the kids.
Also to the topic starter. Your several games to late with the gun that shoots for you. The sentry gun has been available since MW2 =p
When the introduce rail guns is when I quit.