My family is from all over Europe (Germany, Estonia, Spain and Portugal) and I've lived over there and Brazil.
In my experience what you described - about some immigrants not wanting to blend in - is seen everywhere and it makes me angry.
I mean, you left you region, which has its own traditions and rules, to move to another region which has its own set of rules. What do you do? You LEARN them. Pay respect to the people and country that you chose to live in.
Unfortunately it seems some dont give a f*ck about that, and try to impose their home country beliefs on the local populace. Thats just wrong and a huge aspect of why immigrants get bad rep. Not unjustified in my view.
I'm aiming to do my Masters at Finland, Sweden or the Netherlands. However, due to those people I'm concerned about my reception there.