I guess with WW2 type subs you mean Submarine. They don't fire cruise missiles, the graphic shows torpedoes going away. First, there are long-range torpedoes (if I remember correctly, both the Russians and the Japanese have such, I guess US have such also). Second, I think the range is there for the submarine to be useful at all. This since submarine detection is automatic in this game, so the only chance you have is to attack from just outside the detection range.
In submarine warfare it is logical. Not the range in CiV perhaps but CiV is an abstract game. But submarines run much more silent than a surface ship and most of them also have much better sonar range than surface ships.
Ask far as actual submarine bugs go... anyone else have them not animate when firing on frigates or earlier ships? They animate just fine vs ironclads and later (especially destroyers) but vs earlier ships they do quick combat instead (even when option is off).