... yes they have their customs, nothing to do with us. I am not exactly sure what your problem is, how people are in their own countries or how difficult people from other countries find it to adjust when they come here - surely you don't expect women to take off their burkas if they find it offensive. Or start eating pork sausages and burgers? Or change their religions? Or stop speaking their own languages? Or start going to pubs?
I am an alien too.