Simple, while commander in my opinion only needs a few tweaks (only my opinion I guess), commander is probably one of the least played positions ingame.
Plus, not a lot of radios on the newer maps, which sucks because then no one can have a commander.
My suggestion: placing radios on newer maps and giving mopre incentive to play as commander (without making it an ideal position for a combat soldier). It was bad in BF2 because anyone could just take slot f it was empty for once and use arty, supplies, UAV, for their own use and never gave commands. If you had some kind of incentive that didn't make it something for a combat soldier (such as perhaps more incentive follow commands so it kinda works up chain, or perhaps the ability to spawn a limited number of AT guns or MGs at each flag?)
And on a slightly less relavant topic, what if commander could spawn a very small limited number of AT guns and MGs at each flag and place them? I doubt it, but just a thought.