Everyone complains about SS yet many do not do ASW because the exp you get is low.
I would suggest that a small award of some type be given to FF, DD, or Cl that sinks SS.
It could be given during events or even during regular battles.
It could be as little as 1 olive for every ss sunk during an event or just an exp boost, amount determined by SDE. Supposedly you get an exp boost for sinking a ship with tuning. So, it ought to be possible to give an experience boost to an FF, DD, or Cl for sinking an SS. Whatever the reward, SDE can determine the award.
The award given to FF, DD, & Cl players, who are usually lower level, more of an incentive to play GBs. At the same time, it might lower the "grousing" done by many of the higher level players that complain about the strength and stealth of the SS.
In many threads, there are complaints that the use of SS unbalances the game. By potentially adding ASW ships, the game becomes more balanced if it is truly unbalanced.
In terms of historical realism....(I know, this is just a game), the FF and the DD becomes the subchasers that they were historically.
Having done a lot of ASW, I know for a fact that it is one of the more difficult jobs in NF.
There should be more of a reward.