I really agree with you, but there arent only SNAC, the nova torpedo does more damage, with lighty more refire rate, a better range, (4.200m) and they are guided. Yes, you have only 70 ammunation, but they works really good against gunboats. Some days ago i beat a liberty gunboat with my berghest fitted with two Torpedo launcher just drifting 2k from hit and spamming guided torpedo. Obiuvsly he can try to destroy the missiles shooting at it, but is really really hard.
In the final yes, cruiser are too bad balanced,an easy target for fighter and bomber. They are only good against gunboat and against other cruiser. stop.
They REALLY need a boost, but primary they need a role.