If you are serious about providing cover for team based objectives or covering your teams back then having your score cut by half won't kill you. There are areas on this game that are seriously hard to take control of without using radiculous amounts of flashbangs and explosives. While everyone loves a good COD style explosion unfortunately we can only bring so much.
you make an interesting post, but the entire complexity of not allowing someone to play the game as they want is my concern. Let them camp, let them wait, hide, what ever.
Treyarch has already attempted reducing the total hiding factor from the game, it is what it is.
It still allows them to play how they want; its a motivator. Hey you want full points don't be like Opum on Saving Private Ryan. Get out there, throw down, or atleast try.
TDM and FFA are probably the only game modes which don't already punish campers the way you've suggested. All of the objective-based game modes do, in that anything done in relation to an objective gets you far more points than kills do. Easy example, in Domination you earn 50 points for capping your home flag, 100 points for a kill, and 200 points for capping any other flag (including recapturing your home flag should the enemy take it). You get 125 for killing an enemy on or near a flag, you get 200 points for killing an enemy while you are capping one. Simplest terms:
Camper caps A at the start, then settles into his corner and runs off 10 straight kills. He's earned 1050 points towards his scorestreaks.
I cap A at the start and move forward towards B. I kill two people on their way there, and then 1 more while successfully capping B. I back off the flag & move into an area where I can easily get back to B, which pays off as I collect 2 defends, a straight kill, and a 50-point assist. I've also earned 1050 points, but in a fraction of the time it took the camper and while only needing to collect 6 kills.
I do still see my share of people lying prone in one place for the entire game, but whatever--they paid their $60 same as me & earned the right to play however they want. It bugs me a little when they're on my team because that means the rest of us have to work harder to get the win, but when they're on the other team I welcome it: they're not stopping me from winning, and eventually in the course of navigating the map I'll end up behind them for an easy kill anyway.
Some people don't like to constantly run around the map. They might be on the bitter end of lag comp, or just not have good enough reflexes or aim to be competitive going full sprint to firing. I personally prefer to find an area on the map I like and patrol it. Sitting still waiting for someone to come to you is boring. Holding an area, moving back and forth isn't bad. If I'm camping, so be it.
I am talking about sitting in one spot, not moving, or hidding in a corner. Holding an area you're moving from spot to spot checked different avenues of fire. In this aspect difficulty increases along with your risk.