What you said is right most of this incidents I heard was based on london.
This is one thing i noticed like you said people speak in their native language especially when people who don't understand them are around ( Hispanics mostly have trouble because of that) , similarly being loud while talking people from my place we don't talk very loudly, even if you go to a good restaurant you wont even hear what the person in the next table is talking ,from my understanding British are like that but if you go to other parts of my country people are loud. Similarly playing loud music that is a big issue .Another one food habits I myself an Indian but trust me I cant stand the smell of turmeric, when my mom cooks I just go out be cause it is too much for me ,I can eat it but the smell is too much.Bringing 3rd world culture that is another one in most of the 3rd world countries people are extremely rude which is normal for them (especially in asia with the exception of latin American nations) and even when they do business they cheat the customers. There is a restaurant in Houston called biriyani pot ,the food is really good but I don't buy from there because one day I saw the way he behaved to a customer. So it is not only the natives the foreigners are also a part of the problem.
