I like that it’s ugly, because it keeps the city empty and cheap and it keeps away the non-serious. There are not many (any?) splashy major sights. Even the Wall is mostly gone. The way to see and experience Berlin is to do things. The ugliness selects for people who want to enjoy the city’s musical, theatrical, museum, and literary treasures.
Berlin is evidence that most tourists don’t actually care so much about history, culture, and museums, as it is not for most people a major tourist destination, despite having world-class offerings in each of those areas. Mostly tourists like large, visually spectacular sites, or family activities, combined with the feeling that they are taking in culture or seeing something important.