1) Orchestras are notorious for gearing most, if not all, of their advertising dollars towards season ticket subscribers. Most of the time, younger audience members do not buy subscriptions. We're too busy to attend a series of concerts or we don't have the cash. The subscription pricing model, in my opinion, is probably the main barrier of entry.
2) School music programs have tiny budgets compared to school sports budgets. Maybe this is a side effect of American culture. Some people really do think sports are more competitive. There is a clear winner and loser. I think the idea of mercilessly crushing your opponent with sheer strength is appealing. Perhaps Suzuki (of Suzuki violin method) was on to something when he instituted a level system comparable to Karate belt rankings.
3) U.S. media completely ignores the classical music scene in favor of Teen Idols and Pop Culture. See: Hannah Montana, Justin Bieber, Rebecca Black... A lot has been written about the false dichotomy between "Classical" music and "Pop" music. This is not a question of talent, although you could argue that teen idols are popular because they are average. As far as I can tell, the main difference is that classical music is advertised poorly and has poor media visibility. There's no good reason that "E! Online" can't cover Lang Lang or Hilary Hahn.
Nodame Cantabile (wiki) is a Japanese cartoon (anime) geared towards high school and college students. I would say it fits into a comedy/drama category. The two main characters are Nodame, an aimless, female pianist, and Chiaki, a piano/violin/conducting prodigy that is top of his class. They attend various college conservatories in Japan and France and go through all of the struggles that music students in the states go through. They have personal goals, they want to be respected by their peers, and they constantly struggle to balance practice time and their social lives. Sound familiar?
The anime, sponsored by Yamaha, includes lengthy and dramatic sequences featuring orchestral music by Beethoven, Mozart, and Rachmaninov, solo piano music by Chopin, chamber music by Schumann, and even Lalo's "Symphony Espagnole," for violin and orchestra. Most of the musical performances are top quality and at the very least, serve as a gateway towards other great classical works. Unlike "feel-good" music movies like "Mr. Holland's Opus," or Meryl Streep's "Music of the Heart," Nodame Cantabile actually has a strong undercurrent of deep respect, enthusiasm, and excitement towards classical music. More than that, it actually paints a fairly realistic picture of conservatory life. The show was so successful in Japan, that it has lasted multiple seasons and even spawned a live-action spin-off.
Nodame Cantabile proves that if you have something actually meaningful and worthwhile, you can market it easily to a youthful audience. The series is credited with actually increasing sales of classical music in Japan. For some reason, youth advertising and animation (one and the same) in the U.S. tends to cater to the lowest common denominator. See Cartoon Network.com.
Though not available on Netflix or officially anywhere in the U.S., I'm sure the average internet surfer could find an English Subbed version with little difficulty. "Nodame Cantabile" is not alone in art-themed anime. See also "Honey and Clover" (a painting/sculpture focus)