BC's don't have shields that quote is not serious it's meant to be comical. Also, a BC needs to turn itself to shoot the Yamato Cannon, the only real weapon it'd have against the Klingon vessel, and BC's are slow buggers in manuver, so the Klingon's could just get out of the way. Also, lasers cannot hurt a Klingon hull, nor can they hurt Federation and I think Romulan. An example is in one eopisode where a ship armed with lasers threatens the enterprise and they deactivate all their shields because their hulls cannot be damaged by lasers almost at all. You'd need to pound on them for like 3 days before you got through. As said the Klingon's weapons are far too powerful.