All kinds of things get called ugly. And ugliness is seen as the opposite of beauty.
But these things are tricky. The Eiffel tower and the Albert memorial were described in their time as ugly. Mountains are now considered scenic, but in the past were symbols of wildness, desolation and danger.
Ugly is not so much the opposite, but jarring, variable, surprising. And sometimes violent.
Beauty gets boring. Too much becomes intolerable. Who says the sedating quality of beauty is better than the stimulating quality of ugliness?
Is a B52 bomber beautiful or monstrous? A motorway interchange?
What do you do when you have already designed the iPhone? Or a Ferrari? Just more of the same?
[Stephen Bayley – “Ugly: the Aesthetics of Everything]