Dusseldorf - international?

After being in Dusseldorf for two days I find it strange that very few people speak English. I thought Dusseldorf was an international city, with all the international fashion , hair and beauty-shows. When going to shops lots of people even have problems with telling you the price in English! I find it strange that, when you ask for the price in English, they just answer you in German.

Even at the tram to the exhibition they don't speak English, there is no information in English and at the show-area very few spoke English and there were little information in English. Again, strange....