I think it depends on how different the dialect is...
Swiss German is definitely a language apart from German, especially if Germans need to take classes to understand it if they move to Switzerland.
I can agree with everything this article says. I think that also, languages teach us to be more tolerant of other cultures and viewpoints. I know many people who are severely anti-immigration, who do not think we should provide any multi-lingual services for struggling immigrants. none of these people have ever bothered to learn another language, and thus, cannot appreciate how difficult learning english is.