Reasons for learning German:
These are some reasons that are more or less valid
1 - to be able to travel in Germany, Austria and Switzerland. (or Namibia and Brazil
Not really a reason, since English is enough to travel in those countries.
2 - to be able to have casual conversations in German with collegues, friends and people I meet.
3 - German media: Litterature, texts, radio and TV. There is an enourmous amount of good content in German. Good radio-programs, TV, books, research in German usw. It is enriching to be able to take advantage of this, and it probably gives an other perspective than the dominant English language media does.
4 - because I had German in school, and have already spent a considerable amount of time learning German. So then I might as well continue, or it have all been in vain. Not a good reason, but still...
5 - Because I learn more about my native language from studying German, both since they are closely related, and also since Germany for a long time was a cultural center in Europe and has exerted a significant influence.
6 - because I like the language: it is solid and rich and with an internal logic. Its complicated grammar means that it is possible to express ideas accurately and elegantly. Even if I sometimes am annoyed by those long sentences with subclause after subclause, where the most important word will not appear untill the end.