William Touhy's article is shockingly superficial, insensitive and thus destined to promote (already existing) prejudices toward German as a foreign language and language learning in general. Even the jokes about Charles V (who never learned German and was therefore targeted in German jokes of the time) or Goethe (who was fluent in many languages and could have afforded to read some of his works in French if he wanted) are hardly funny since they are told without an understanding of the respective context and background.
The fact that German has been declining here in the United States quite substantially (the decline is much less dramatic on a world-wide basis) does not have very much to do with the "complexities" of the German grammar etc. as suggested; as a matter a fact, German is hardly more difficult than French, Spanish or any other European language and it's, of course, very closely related to English! No, the closing of many college departments of German or the fact that German is quite often not even offered on the high school level (for instance here in Los Angeles), not seldom against public demand, has foremost something to do with the dismal financial situation of most public (and private) schools and the overall deterioration of the quality of high school and college education.