Because there is nothing to solve? Do you consider this a serious question that needs a particular answer? Does the question "what is better coffee or tea" make sense and requires such particular and ultimate answer? No, because it is a matter of opinion and current requirements/conditions. Same with our topic - "aesthetics and art-style/artistic design choice VS realistic approach/representation". There is no question or issue in a first place, it just makes no sense to bring up this question at all. Two sides of one coin.
Coffee and tea? That's a strawman argument if there ever was one. That is, truly, a matter of opinion.
The 'feminised' armour argument is
much deeper. It ties into many problems in society, such as the objectification of women and a male-dominated view point. Don't believe me? Well, then, why aren't men wearing armour that highlights attributes of theirs? Why aren't they walking around all buff, oiled and so on? Feminised armour, however, emphasises the breasts, and often leaves parts of the wearer exposed.
Do you truly think the armours of the main characters in the Original Sin art work are in any way equal? The guy is covered from neck-to-toe in plate, mail and cloth. The woman? She's wearing a metal bikini, some boots, gauntlets and a few other bits of armour. Her cleavage is exposed, her bikini follows the outline of her breasts, her waist and legs are also visible, and her upper arms are largely bare. She is wearing very little protection, whereas the guy is in lightly-exaggerated full protection.
If you don't see an issue, well... bully for you. But there
is an issue, one that has been part of gaming for many years. It will
not stop being an issue unless people start to speak up about it. I'm speaking up about it. I'm doing my bit to try and stop it being so common.
And as for your first bit about the production - they're designing the armour anyway. They're creating the female models, the female textures and so on. It isn't going to cost them any more (will actually probably cost them less, as I've stated before, as the female versions will just need to be tweaked from the male ones) to implement 'proper' armour for women.