I live in Berlin and I can explain the problem quite clearly. The issue purely is that there isn't sufficient capital here (still) to sustain the supply of art. Compared to a city like London or NYC where there is a really healthy market of art patrons.

There is a very clear divide between creatives (artist, musician, videographer, photographer, etc.) who are at the beginning of their career, and those that have achieved some success. The beginners are still trying to make their money in Berlin. The somewhat established creatives make their money outside Berlin, but use Berlin as their home base because of the cultural connections and creativity it generates.