So, a poster named Carfish had a funny take. I won't go into details, its on page 7 of the discussion, but his money quote comment is here (you might have to read the previous page's postings to understand how it ended up here.
Catfish at rpg.net
Which is why accurately drawn boob armor creates the 'bikini' effect: the plates cannot be made any larger while still retaining their structural integrity. A breastplate that covers much more than a woman's areolas would literally disintegrate in real life.
It's not sexism - it's realism.
So that explains this
But not this