Well, I think the argument does matter from a gaming standpoint. Every generation of games has gotten progressively easier to play, and progressively easier to "win." Winning has been redefined, so that it encompasses more people. PvP style games are less abundant, as it's more important to play with a team. Single-player games are strongly encouraged to be easier, and have online options.
The point is that games have become easier to appeal to the general population. The problem this creates is that easier games breeds poor gamers which then require even still easier games - hence a downward spiral of game difficulty. This also tends to create games that are identical to one another, using the same engines, texture libraries, control schemes, etc etc -- because these gaming schools dictate the idea that you should be able to pick a controller and play, without any need for reading or testing. This means that if one game mechanic becomes incredibly popular, then all other games should have a very good reason for doing something different. This is both good and bad.
But concisely, the problem that I had with CoD4 specifically, and every version since, is that it became the go-to model for all first person shooters thereafter. Call of Duty became so popular, so commonplace, that even Microsoft has shifted Halo to play more like Call of Duty, rather than just expounding on what they had - which ruined the game for many of us who were very seriously involved in the Halo gaming community (as in MLG, sponsoring, local/regional tournaments, streaming, etc). Halo was a big part of my life because it was my primary tournament at my local game store. I made thousands of dollars on Halo, and other competitive games like Street Fighter at my store. I was also on a Halo team that traveled to play games, and we've had our games streamed quite a bit.
So what changed? Lots of things. Of course the business model changed because LAN games on consoles are a thing of the past. But CoD just isn't as competitive, IMHO, as games like Halo or RB6, Unreal Tournament, or even BF. So when kids want to play a game, they'll want to login to XBLive (no more in your face LAN games with people screaming) and play CoD, die a thousand times, and it's okay - they leveled up. Rush for weapons? Nah, I got my load out.. I earned it a hundred deaths ago...
Whereas in a game like Halo, how many times you die is of equal importance to how many kills you get. And there are no advantages that one team has over the other. It's a more skilled based game. And this can be said for different games for different reasons based on their game mechanics. But from my experience with CoD:MW1-2, this is completely the opposite. Starting out in the game, the team is really irrelevant, as is the preceding battle. Whether you win or lose, it doesn't matter, because you're instantly rewarded with +XP on the individual kill! Leveling up becomes addictive, and all of a sudden, the battle is just the backdrop for getting a maxed out character. Everything else is really just of secondary importance.
So that's why I, personally, have a problem with CoD, and think it's really just destroyed the FPS competitive gaming community. Unfortunately this gaming concept has spilled over into every genre that I like to play including RPGs, Action, Adventure, and sadly Fighters.
