Obviously, Classic game modes remove the Exo suit from the equation and gives you more of a traditional CoD experience. Have you spent much time in this mode?
I tried queuing for games in this mode but there's hardly ever any active players! Personally I'm not a fan of the Exo suits so I'd be glad if more people tried out this mode in multiplayer.
Most people that want to play without Exo suits are probably playing different CoD games, to be honest. It's true the playlist is sometimes lacking in number of players available, and that's a slight issue.