Revealing armour is ridiculous when it's for titillating purposes only, i.e. when it's for women only while men do wear full plate.
If revealing armour is internally consistent with the setting, like in Hyborian Age (where men tend to fight with bare torso), I have no problem with it.
The opposite of coin are settings where both men and women wear ridiculously big and elaborate armour, like World of Warcraft and Warhammer.
