They turned it to max from aw onwards , the series has been around for so long it has plenty of vets playing and was getting harder and harder to keep new players interested when they were getting pub stomped every game.
Sbmm is there to keep new players and build on the player base by putting you vs the same skill players rather than coming in new and facing off against 10 year vets and having a horrible time with the game, moving on quickly and not buying the next 1.
Sad reality is its turned the game for anyone half decent into a sweat fest and killed the enjoyment of mixed lobbies, even if you was good it wasnt like you would win every game unless u had a crew of sweats with you but as time passed that became the norm and is another reason sbmm was implemented.
Bottom line the good old days of cod are dead especially for good solo players, battle royale is where the cash is and will be the main focus moving on and we basically need a new fps from to freshen things up at this point.