Gents,
In World War II, submarines were only rarely targeted against capitol ships. Combat Task Forces were just to dangerous a target for a submarine to tackle. The large part of submarine operations were in logistics, anti-logistics, reconnaissance and other operations. These operations do not fit into the focus of AHII. On top of this point, AHII has no model built in the simulation for Antisubmarine warfare. Therefore there is currently no place for submarines in AHII. 
Tull
Sure, all that is true. Submarines were almost of purely strategic operational value and were rarely used as tactical weapons - with exceptions as you note for things like recon. Thus, your argument is very sound.
Now picture what some acehole could do by jumping into one of the a-hole conveyances and blindly firing large salvos of torps at anything and evvathang. Hooowee. It'll put the arcade a-hole right into the driver's seat - and that's a good thing.
Right after they add the blind-firing indiscriminate Unterseeboot to Aces High, they should also add a BFG-9000 so that some total arscheklown can stand in the middle of an airfield and unleash an energy burst that'll cripple the approaching horde and score him 50 bazillion KILLZ, name in lights an' evvathang.
Empowering the juggalo buttklown should be the focus of future AH development. It's a pity they've stuck to things like immersion and historical accuracy when a good EMP weapon could bring down all those silly l'il junk planes. What a bunch of anachronists.