How Can Lisbon Have All the Worlds Best Hostels?

Thuy Thuy Hotel Pool - Mui Ne, Vietnam
I've been to Lisbon, I stayed in a couple hostels there. They were nice, but if I were to come up with a list of the top 5 hostels I've personally stayed in (and I've stayed in a lot), no hostel in Portugal, let alone Lisbon would make it. Look at the 2011 Hoscar Awards, which HostelWorld gives out each year. The top 3 (out of the listed 3) hostels worldwide are all from the same city! Lisbon or anywhere else, how can one city host the top 3 hostels in the world???