That's exactly what MW3 did and I have no idea why rangers thinks that's awesome. It's terrible and ruins the mode IMO.
Demolition as it originally was (and is now in BO2) was like, uh, I don't know what it's called in english but when two teams pull a rope and try to make the other team fall? That. It was glorious. MW3 Demo is just a stupid clusterfuck that makes no sense.
You can learn cutoffs in MW3 demo though to kill them somewhere between from where they spawn and the bombs.
2 examples real quick:
1) Hardhat. Such a small map, yet somehow you don't get spawnkilled on it. On offense, you either spawn in the 2 story building, by the double stack of newspapers where people head glitch, or by where the overtime bomb placement is (in a corner near the truck trailer thing). Also, when A is the last one remaining/planted, you either spawn at the newspaper stack or where the defense initial spawn is. One team gets one of those spawns and the other gets the other spawn and they are equidistant to A. If your team pushes both spawns, then enemies spawn by B demolition and usually take the tunnel. Rarely does it happen, but you can spawn on the B bomb if all other spawns are taken. The same goes for defense. If you plant and then push up to there spawn to the point where they have nothing left, they'll spawn on B and get a defuse, but for the most part neither situation happens.
2) Better example. Bakaara. Offense spawns either where they initially spawned, where B domination is or (pretend you are starting off the round and you run down the street and make your first right) thats the last spawn. I've never seen a spawn on a bomb on that map. If you push street, they spawn B dom and if you push B dom, they spawn street, which makes most of the battles on that street to B. Defense can spawn B dom or by their initial spawn. One person might say it's spawn killing when you spawn at B dom, but if you look to your right to see them coming from the street, you can kill them, or you can just not run forwards after u spawn into their line of sight, but take an alternate route.
I still feel like it's pulling the rope, without the spawn and die immediately bs. I still know there spawns and can easily kill them, but i can't watch them spawn and kill them or hang around the area behind a wall or something and then pop out. I will give it to you that they spawn on bombs occasionally, but thats usually your teams fault for pushing up to a certain spot. I know it when I do it.
And if the offense pushes up and plants, then the defense starts spawning where the offense originally did, making the task of defusing just as hard as planting is.
Sorry for the long post. :/
EDIT: Not saying you do this, but most people that like the old spawns that are set are people that like to go into the enemy spawn and spawnkill them. They ignore the bombs and run right past them to your spawn. Or the people that did dome 24/7 lobbies. The dome 24/7 is what got them to patch the spawns in the first place. Other people that I know that weren't big spawnkillers hated it at first because it was a change and they didn't know where enemies were coming from, but love it now.