what's beautiful about clothes is that they're things that you could easily change and replace. they're external. they can be used to make you look a certain way only if you know what you're doing and if you have the resources to make it happen. vertical lines make you longer, horizontal lines make you wider. these are old rules. if no one who is a plus size wants to look fatter than they already are, why do we still have plus size clothes with horizontal cuts in their dresses? because there's more to to the rules than straight forward horizontal and vertical.
not everyone we design for will be model size. there will be horizontally challenged clients in our lifetime and we'd be forced to create something to make them look great. I don't understand how seasoned designers prioritize their creative point of view and create something that only looks great on a mannequin. not everyone who graduated from design school are successful as designers because not everything that looks good in books translate well in the real world.