I don't have very strong opinions on this either, but I think it's more of a desperation maneuver than a cheap gaming tactic. During WWII, you had mutual protection within a massive formation of bombers. In this case, the worst thing you could've done is dive away to separate yourself from the pack. In AH, if you see some 190s closing in on your lone bomber formation, you're more likely to just make a run for your target by pushing the nose over. Keeping in mind that level bombing involves manning the gunner positions, calibrating your sight, and most importantly, flying the airplane, dive bombing will greatly increase your chances of survival by eliminating that one extra step.
Buffaloo