I would hardly call it a glitch when the perk is working as it was intended. The problem is that the SAM turret and Sentry gun are just care packages with a 100% drop rate for those particular killstreaks, so the perk does it's job and gives you a chance for another killstreak, nothing broken about that. From a game balance perspective yes it should definately be fixed.
Plus the killstreaks would be no problem at all if people would just shoot them down as soon as they appear, but it's mostly left to me (you do help out aswell), but most peoples attitude is "lol ghost pro not my problem", people have no excuse now not to carry an anti-air launcher as their secondary because what is there really worth having instead other then crap like RPG's and crossbows to mess around with?
I think it should definately be patched out, I would be amazed if that's the intention. I think it's just slipped through the net. I hope it gets patched out fast.
Sometimes you can't shoot stuff down, not everyone has ghost pro and if constant chopper gunners are up it can be tedious on an objective game.
Regardless all of that could be fixed by giving 5xp for a kill and 1000xp for a capture or objective. They should also add shooting down killstreaks to the person getting them. Reward people who shoot them down.