I personally love destoyers, and i often ambush BB with them. But most of the destoyer kills comes from BB captains moving their massive ships into narrow spaces, where they have to chance of dodging or them setting a course the first secound of the game and never changing it.
Attacking a BB in open waters is often suicide. 1 hit to the citadel can sink a destoyer.
A better solution could be to have a serious instruction for the ship classes before you can join matches.
If you ignore a spotted destoyer long enough for it to get within a kilometer or two, you deserve every single torpedo you get.