REALISM!!!People wore armour for one reason and one reason alone: To protect themselves and if it didn't allow you to be mobile while wearing it, it failed one of the design keys to making armour. It never made much sense why a hulking great warrior dressed head to toe in steel would be taking the same damage as a thin, reedy dude in his wizard hat and robes when both get stabbed with a dagger. Realistically (urgh, seriously?) there would be heavy DR properties for each type of armour, even a boiled leather cuirass can turn a sword blow very well.
Inversely, plate mail wasn't designed to be worn 24/7 though in campaigns, there are many accounts of nobles being forced to sleep in their armour due to impending attack. They aren't pleasant accounts as far as relieving yourself goes. If you wore armour indefinately, you' have -10 charisma from the smell of stale sweat, piss and faeces alone.
Fear not though ye playboy swordsmen who want to fight battles AND dalliance with the ladies. There is a rare loot drop one can aquire in game. Tis the Armour of Comfort, a very nice banded mail that only weighs 8lbs and is magically imbued to smell like lavender. BANG!! And the smell is gone.