As was pointed out, ancient Greeks deliberately emphasised false muscles on their briastplates to intimidate their foes. Keep in mind that certain mythologies such as Greek and Norse had very powerful goddesses as well as gods. Emphasising the female briast is not at all against the culture or the military intent of such societies. It would be for intimidation purposes, not anything regarding some sort of need to hide the female briast or consider practical physics.
Also, I found it odd that some people claimed that ancient people did not have sophisticated math, physics, etc. Actually, they did, as many archeologists and anthropologists would tell you. That's why they were able to make not only the armor and weapons they used, but also buildings, artifacts, and other elements of their cultures.
People who hate "boob plate" must also hate the "peck plate" I suppose. That's ignoring history, though. However, as I said, Earth history doesn't matter for a fantasy game setting. The same rules do not apply. The problem is the player's perceptions and assumptions, not the game.
I hate the boob plate. I think it's stupid. Peck plate, however, is nowhere near as impractical as boop plate. Pectoral muscles, even idealised pectoral muscles, are smaller than the overly generous busoms ingame and envisioned by game developers, the armor is also usually molded leather, or thin steel. Not a heavy briastplate.
Also, the two cultures who most prominently used idealized pectoral muscle armor:
did not use the body armor as the primary form of defense in their warfare. Greek, Roman, and Macedonian warfare were fought primarily with the shield as their first defensive tool. Most of the idealized armors were also only worn by the Generals in order to show off how superior looking they were to inspire their men.