BBs are intended to have lower DPM than cruisers. Why would anyone play a cruiser if the vastly more survivable class did the same or more damage?
BBs get more real damage by getting close to their targets to minimize dispersion and killing them before they have time to repair up again, neither of which cruisers can really do unless the enemy screws up.
But then from your comment on torpedoes it's clear you have no interest in logical arguments.
If anyone in this thread is actually more interested in improving than arguing, shoot me a replay of a game in which you believe you made no mistakes and still lost by a small margin, and I'll show you where you could have made the difference.