It’s changing the culture and whether that change is good or bad is a matter of opinion. I can see where people who think their culture is good the way it is now and don’t want it to change are coming from. I’m an immigrant myself (in the USA) and I think I’m as American as most native-born Americans in some ways but not others. I like to think that my net contribution has been a positive one by any reasonable metric, but I admit that I’m biased towards economic metrics. Someone who values cultural continuity very highly might disagree.