I think ornate armour is okay as long as:
1) It's restricted to important people. Fancy armour is a status symbol. If common soldiers could afford it, it would no longer be a status symbol and in fact no-one would wear it. Colourful uniforms are okay, as they serve a function, allowing units to be identified from a distance. If all soldiers are nobles, they can all wear ornate armour, but there can't be 50,000 of them.
2) It's not compulsory. Ornate armour was custom made, and those who got it could choose their own design. The player should therefore not be required to wear ridiculous looking armour just because they need the plusses late game. There should be some plain, high level armour. Ideally, it should be customisable, but since that adds a lot of work for the dev team, they don't have to.
3) Features that would clearly be detrimental to performance should not be included, unless the armour is strictly ceremonial. Big spikes would be a liability, some peasant would jam his pitchfork into them and the wearer would be unbalanced. And if a woman wants to be nigh indestructable while wearing very little, she must use magic or advanced technology. Pretending that a metal bikini could offer her real protection is just silly.