Looks like this is kind of a U.S./western-centric issue? I think it makes sense for people to learn the language of the country they're moving to. But I don't think it should be mandatory, and in my experience with other immigrants, I've never met anyone who actually refuses to learn English. I'm a first generation American so most of my family are immigrants, and I live in Southern California so there are a lot of people from Mexico here. All of my family, except for my grandparents, speak fluent English. Most of them still have accents, but that's not something you can help. I honestly think most people DO try. Heck, even my 75 year old grandmother is trying to learn English.
If anyone can provide any studies or information on whether or not most immigrants are intentionally refusing to learn English and how that impacts society, that'd be really helpful. Because based on personal experience and from what I've read, it's not that big of an issue. People come from all walks of life, the world is getting more and more interconnected... as far as us native English-speaking people go, we should probably be learning other languages too. I think the bigger problem has always been the prejudice towards people from other countries. Folks who don't speak unaccented English, who are still trying to learn, or who are obviously "foreign". People look down on that, and it's really sad.