Part of my background is in visual design as well, and I think you have some great points. On the other hand, one has to consider the overall point of the black PA. It is about formality with classic lines. And formality is much more about conformity than interest or preference. The purpose of the black PA is actually the opposite of interest in my opinion. It is supposed to blend in to the rest of the attire, creating strong masculine lines that ground a dark masculine suit. Black PA's are more about showing one's character than one's personality. They are more about showing respect for others and the event to which they are worn than individuality. A well dressed man in a dark suit and polished PA's always looks sharp, because it reveals a man of character with the humility and respect for tradition that allow him to confidently express his personality in the minute details of his attire (e.g. PS fold, tie knot, overall fit) and the person on his arm or at home.
Don't get me wrong, I love a walnut strand and my chili universities, and I don't even own a pair of black PA's. I don't own them because I find the FA's more versatile, but I can't deny that black PA's do their job extremely well.
What's the most casual you will go with your FA?