By this logic, English-language opera (yes, it exists) ought to be doing well in America. Check your local opera house schedule and see how many performances you can find that are not in Italian, German, or French.
There is some merit to this argument, that some music can't be appreciated as easily unless you attach it something people can easily relate to. Even classical music isn't immune to this, hence the existence of program music like Beethoven's 6th symphony and many other works from the Romantic era. Today, it's mostly film scores that fall into this category of instrumental music that is best understood within a certain context.
I think the difference today is that the context itself has changed. We've transitioned to an urban, fast-paced lifestyle and have lost touch with the beauty of nature from which many instrumental pieces draw inspiration. We've become more materialistic, hence the prevalence of "bling" in rap songs. The host on my local classical station once remarked that there are only two serious topics in music: God and sex. Though I'm not religious, I can tell that these days it's much less of the former and more of the latter.
That said, I wouldn't be so pessimistic right now. Think long-term: in 100 years, how many people will still be listening to Brahms, and how many will still be listening to Britney Spears?