Look at Halo 2 Anniversary though. This is what Halo 4 should have been. Even someone who's never played a Halo game in his life, can pick up Halo CE, then play Halo 2, then play Halo 3 and then play Halo 2 Anniversary and it will play like he expects it to. The base gameplay is the same across those games. Halo 4 is the odd man out. Infinity settings and launch gameplay was so different, it was inevitable the community would be split.
Compare Team Slayer to MLG/Hardcore settings. The only differences are slight changes in movement speed, health recharge, different weapon spawns and starts, and radar off.
Now compare Team Slayer to Infinity Slayer. You go from no sprint, on map weapons, equal starts, descope when shot, to sprint, global ordnance, personal ordnance, loadouts, perks, and things like flinch when shot. Add in other things like instant respawn as well.
I don't mind if things like Infinity were in one playlist only. Some kind of action sack playlist. They could have even called it Duty Calls playlist. Gameplay has unlimited sprint, melee is instant kill, all the perks, loadouts, personal ordnance needed, radar only makes you visible when fired. That way team Slayer, BTB, objective, Slayer pro and every other part of the game was free from it.