Alright, let's see if I can do this without starting a flamewar, I think I can manage it. *cracks knuckles*
Shooters are generally about skill and team tactics, that is what elevates one team over another in an online match. Here are those two elements, and how the core mechanics of CoD violate and destroy each of them.
Skill:
Basic Definition:
The ability to properly dispatch an opponent due to effective aiming and use of environment (cover and the like) in an even fight.
Call of Duty Definition:
The ability to wait in one spot until an enemy walks by, and then kill him solely because you sat in one spot and happened to see him first.
Violating Mechanics:
1.) Low Health (or high damage)
The extremely low health in CoD means that when two opponents are within range of eachother, and overwhelming amount of time the victor is the one who sees his opponent first, not the one with the most skill.
2.) Prone
Prone allows a player to lie down and almost always be the first person to see an opponent when the opponent enters the room, and don't even get me started on "drop shooting"
3.) Static Spawn
Besides the obvious problems shown in the video (did you see the part where he literally stood behind them and stabbed each one as they appeared?) Static spawning means that you can reliably predict which hallway/room/alley the enemy players will funnel through, leading to camping spots that take advantage of the mechanics listed above to remove skill from the game
4.) Kill Streaks
Players are awarded for getting a number of kills without dying, which discourages them from taking any sort of calculated risk or put their life in danger for the good of the team, this heavily encourages camping
Conclusion:
I have no real issue with any of these mechanics alone, the problem is that they all work together in synchronization to create a game where the victor is not determined by skill but by camping and waiting for extended periods of time
Tactics
Definition: Increasing effectiveness through the use of proper team communication, strategies, and grouping into squads
Violating Mechanics:
1.) The four mechanics above and the camping atmosphere they create
Grouping is suicide in CoD because the high damage and advantage of finding a camping spot means that a single camper with a rifle can kill three or more people almost as quickly as one, as long as he has a decent camping spot. (as in, any window overlooking a linear path)
2.) Static Spawns & Frequent Deaths
The fact that in CoD players are constantly either A) In a camping spot (in which case another teammate isn't likely to heavily increase effectiveness as detailed above) or B) constantly dying and teleporting back to one side of the map. Makes it nearly impossible to work as a group.
Conclusion:
Given the diminishing returns on camping, and the fact that players are constantly separated by being whisked away on respawn with startling frequency makes it nearly impossible to execute any meaningful teamwork.
Overall Argument
A shooter is not about finding spots to camp on a map, but that's what Call of Duty is all about, leading me to the conclusion that the core mechanics listed above have broken the fundamental aspects of what makes a shooter enjoyable.