No you look to the core fundamentals of what made your game good in the first place
Not "hey lets focus group the fuck out of the game until its an unappealing piece of shit just in the hopes that the 20 non gamers can find their way to an objective"
Competitiveness is a side effect of the quality of a game, by the way. Not its accessibility.
And to your point, you don't have one.
Although i understand your point, if i take the example of Halo2 which a lot of people consider the best one MP wise (not me tho, to me Reach is by far the best), it was also the most noob-friendly of all Halo games. Tracking on Needlers and Plasma Pistols was completely unavoidable unless you happen to be lucky enough to be near a wall or rock thus creating the noob combo (BR & PP), Rockets locked onto air and ground vehicles and took virtually no skill whatsoever, hit boxes were unbelievably huge, etc. This game was the most user/noob-friendly Halo game ever made and look at that, it was the most played out of all of them. Coincidence? Nope.
Skill and competitiveness doesn't attract the masses, fun does. The more average players don't play Halo anymore because the barrier of entry is too high. If they dont get kills, they dont get points, they feel useless to their team and ultimately, have no fun playing the game.
The reason games like COD are so appealing to these same people is because in that game, they can have the same sucky kill/death ratio that they get in Halo, but they get lots of points regardless, and quickly too. Like for being a distraction, for getting a certain number of kills, for running a few miles with the running perk, etc.. You get points for practically everything in that game and it doesn't hurt that it doesn't take a whole clip + a grenade & melee to kill someone. This in the end makes that same bad kill/death ratio in COD a lot more fun to the masses because even if they suck at getting kills, they can still get points, feel useful, unlock shit and thus, have fun.
This might be hard to accept for most competitive players, but its a fact. Its also the main reason why Halo is moving into that direction, because it works plain and simple.
What 343 is doing now from what im seeing is that they`re trying to balance skill and fun, and i think they`re doing a great job from what ive read and seen so far. If you can keep the skill factor of Halo (without the lock-on guns and noob-combos of Halo2) and have people who stink at the game still make points for being a distraction, or whatever else, why not? Everyone enjoys the game more this way and the masses keep playing instead of moving on. It adds longevity to the game and possibly more content for everyone because of that. I like it.