Similarly (from one page later): a Psych textbook used Brahms to illustrate "Sleep disorders" (the general idea), because he apparently suffered from sleep apnea. The Boundless text apparently also chose Brahms to illustrate "sleep disorders".
But you're the one who publicized it! We're only talking about it because you submitted this one-sided blog post. You shouldn't be surprised that a bunch of message board nerds would actually track the filing down.