> The purpose of most buildings is to be useful, not to look pretty in pictures.

Architecture is the only art where you're forced to participate. So we could pretty much say the opposite, buildings should, among other things, contribute to make a place nice. Or at least not make it more miserable.

> What do you think Barcelona is?

Most of Spanish cities are built with crap buildings dating above the 60s. Just concrete blocks, in some cities even with just plain grey and humidity stains. It doesn't matter how historic the city is, because the "historic center" it's just a small spot surrounded by uglyness.