No offense but you have an unbending opinion. One that cannot be changed. If you didn't you wouldn't find the ONE riot we have had here where a hundred kids burned a hundred cars. I live here. I also lived in LA. The Rodney King Riots were a riot. This was a bunch of trouble maker kids burning a few cars and throwing some rocks for a few days until the neighbors came out and yelled at them to stop. I'm not trying to necessarily down play the riot but the scope of it is kinda important.
Regardless your argument is racist. You said that the reason we are so happy here is because we're all the same. I'm telling you that we aren't. It's not as diverse as San Francisco necessarily but it's made huge changes in the last couple of generations. My mother didn't see her first black person until she was in her early 20's.
Racial tension in Sweden are a fact of life just like they are in the USA. People simply fear what is different. It takes time to integrate into a new society. The problem we have here with immigration is that unemployment is something like 8.7% and most of those are immigrants. Once they get integrated and get a job it gets much better but the town that had the riots is filled with people who are fresh off the boat. Population 11,000 people.
My family in the states had a hard time until they learned English and got established. That's the reality of immigration. They are outside of the system in the beginning. I can't just move to Iran and be part of their world. It doesn't work like that.
http://en.wikipedia.org/wiki/2013_Stockholm_riots
Might be worth a look for you since your link didn't actually mention the cause of the riots.