Another thought occurred to me.... Perhaps there were never any Romulan bodies seen and/or recovered during the Earth/Romulan War because of their ships having the Singularity Devices as power. They either blew themselves up on purpose or their starships went 'Ka-Boom' naturally, at a certain point of sustained damage. Either way, when the Singularity lost it's containment field anything nearby would have been totally annihilated. Might even be possible that a few Earth Star Fleet ships could have been lost due to being too close to the explosion (Implosion?) at times. If so, one would imagine that the Admirals back on Earth would instruct/order all their Captains NOT to approach or try to capture any of the enemy due to what appears to be their complete suicidal nature.